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ECONOMIC ENTOMOLOGY 



FOR THE 



FARMER AND FRUIT-GROWER, AND 
FOR USE AS A TEXT-BOOK IN 
AGRICULTURAL SCHOOLS 
AND COLLEGES 

JOHN B. SMITH, Sc.D. 

Professor of Entomology m Rutgers College ; Entomologist to the New Jersey Agricultural 
College Experiment Station and the New Jersey State Board of Agriculture ; 
President of the Association of Economic Entomologists of the Brooklyn 
Entomological Society, and of the New Jersey State Microscopical 
Society; Fellow of the American Association for the 
Advancement of Science, etc., etc. 



ILLUSTRATED 




PHILADELPHIA 

J. B. LIPPINCOTT COMPANY 
1896 



Copyright, 1896, 

BY 

J. B. LippiNCOTT Company. 




Electrotyped and Printed by J. B. Lippincott Company, Philadelphia, U.S.A. 



C O N T E N TS. 



RARo: I. 

STRUCTURE AND CLASSIFICATION. 
CHAPTER 1. 



The General Structure of Insects ii 

CHAPTER 11. 
The Head and its Appendages 14 

CHAPTER III. 
Thorax and Abdomen 23 

CHAPTER IV. 
Muscles, Digestion, and Circulation 27 

CHAPTER V. 
The Respiratory System 33 

CHAPTER VI. 
Nervous System and Senses of Insects 39 

CHAPTER VII. 
The Reproductive System . . • 45 

CHAPTER VIII. 
Growth and Metamorphosis 48 



iii 



iv 



CONTENTS. 



PART II. 
THE INSECT WORLD. 
CHAPTER 1. 

PAGE 

General Classification 52 

CHAPTER 11. 
The Thysanura 55 

CHAPTER III. 

The Neuroptera and Pseudo-Neuroptera , . . 58 

Order Ephemeroptera 59 

Order Odonata 60 

Order Plecoptera 63 

Order Platyptera 64 

Order Neuroptera 72 

CHAPTER IV. 
The Orthoptera 79 

CHAPTER V. 
The Hemiptera, or Bugs 100 

CHAPTER VI. 
The Coleoptera, or Beetles 164' 

CHAPTER VII. 
The Lepidoptera 240 

CHAPTER VIII. 
The Diptera, or Flies 327 

CHAPTER IX. 
The Hymenoptera 370 



CONTENTS. V 

PART III. 
INSECTICIDES, PREVENTIVES, AND MACHINERY. 

CHAPTER 1. 

PAGE 

Predaceous Insects, Parasites, and Fungous Diesases . . . 418 

CHAPTER II. 
Farm Practice to prevent Insect Attack 423 

CHAPTER III. 
Preventives 430 

CHAPTER IV. 
Insecticides 434 

CHAPTER V. 
Machinery 454 



ACKNOWLEDGMENTS. 



The illustrations in this book are derived as follows : Electro- 
types were loaned for the purposes of the work by the Agricul- 
tural College Experiment Station of New Jersey, of figures Nos. 
4, 5, 6, 7, II, 13, 14, 15, 28, 29, 30, 32, 34, 35, 36, 37, 38, 39, 
41, 43, 44, 45, 50, 53, 64, 72, 83, 84, 85, 88, 89, 95, 99, 103, 104, 
105, 114, 127, 128, 129, 130, 131, 132, 133, 134, 136, 137, 138, 
142, 143, 144, 146, 147, 149, 157, 158, 160, 161, 162, 164, 166, 
167, 170, 171, 172, 173, 174, 175, 176, 178, 179, 180, 181, 182, 
183, 188, 189, 190, 192, 194, 195, 200, 201, 202, 204, 206, 212, 
214, 216, 217, 218, 219, 221, 222, 225, 227, 228, 229, 230, 231, 
232, 233, 234, 236, 238, 239, 241, 242, 243, 246, 247, 255, 263, 
264, 265, 274, 278, 279, 281, 283, 286, 287, 288, 289, 290, 291, 
296, 297, 298, 299, 300, 307, 314, 321, 332, 333, 334, 341, 342, 
343. 349. 350, 351, 352, 357, 362, 366, 368, 369, 375, 377, 380, 
386, 387, 392, 393, 394, 395, 39^, 397, 398, 399, 401, 409, 410, 
411, 412, 413, 416, 417, 418, 419, 424, 425, 426, 430, 432, 434, 
435, 437, 438, 440, 441, 444, 445, 44^, 447, 448, 449, 450, 454, 
455, 457, 458, 459, 460, 461, 462, 463, 464, 465, 466, 467, 468, 
469, 471, 473, 475, 480, 481, 482. 

By the courtesy of the Secretary of Agriculture and of the 
Division of Illustrations in the United States Department of Ag- 
riculture, electrotypes were obtained for figures Nos. 22, 23, 48, 
56, 58, 73, 74, 75, 76, 81, 82, 86, 87, 90, 91, 92, 93, 100, loi, 
112, 116, 117, 118, 120, 121, 122, 124, 148, 151, 152, 168, 193, 
198, 209, 223, 224, 226, 244, 245, 292, 293, 294, 295, 315, 316, 

318, 339, 340, 358, 360, 363, 364, 365, 371, 374, 376, 383, 389, 
390, 391, 402, 404, 405, 406, 407, 408, 431, 452, 474, 483. 

The J. B. Lippincott Company kindly loaned the following 
from Saunders's " Insects Injurious to Fruits" : Nos. 55, 59, 60, 
61a, 65, 79, 80, 94, 97, 98, 102, 109, 125, 159, 165, 169, 191, 
197, 199, 203, 211, 213, 220, 240, 254, 259, 270, 271, 275, 276, 

vii 



viii 



A CKNO WLED G ME NTS. 



^11^ 284, 302, 308, 309, 310, 311, 312, 313, 324, 325, 326, 327, 

328, 329, 330, 331, 337, 338, 347, 353, 354, 367, 372, 373, 400, 
403, 422, 428, 429, 443 ; and from French's "Butterflies of the 
Eastern United States," Nos. 253, 260, 261, 262, 268, 269, 273. 

From Prof. Lawrence Bruner, of the University of Nebraska, 
were purchased electrotypes of figures Nos. i, 26, 31, 33, 42, 46, 
47, 51, 52, 6ib, 62, 68, 70, 71, 96, 107, no, 115, 139, 140, 141, 
156, 163, 186, 256, 319, 320, 335, 336, 355, 421, 433. 

From Houghton, Mifflin & Co. , pubHshers of the ' ' Riverside 
Natural History," were purchased Nos. 12, 17, 77, 78, 106, 177, 
378, 414, 423, 451, 472. 

From the Entomological Society of Ontario electrotypes were 
obtained for figures Nos. 207, 208, 258, 420, 456. 

From the Cornell Experiment Station, through the kindness 
of Mr. M. V. Slingerland, electrotypes were secured of figures 
Nos. 40, 119, 145. 

Mr. G. C. Davis, of the Agricultural Experiment Station of 
Michigan, furnished stereotypes of figures Nos. 196, 235, 301, 
370, 388, 439. 

Prof Herbert Osborn, of the Iowa Agricultural College, kindly 
loaned for reproduction figures Nos. 108, 356, 382. 

Dr. Otto Lugger, State Entomologist of Minnesota, supplied 
electrotypes of figures Nos. 280, 427, 442. 

Dr. F. H. Snow, of Lawrence, Kansas, loaned for reproduc- 
tion figures Nos. 123, 210. 

Mr. F. M. Webster, of the Ohio Experiment Station, per- 
mitted the reproduction of figures Nos. 205, 237. 

Mr. A. D. Hopkins, of the West Virginia Experiment Station, 
granted the same favor for figures Nos. 384 and 385. 

Dr. A. S. Packard kindly supplied electrotypes of figures Nos. 
16 and 470. 

To Dr. G. Brown Goode, Director of the United States Na- 
tional Museum, I owe electrotypes of figures Nos. 27 and 381. 

From Mrs. C. V. Riley were purchased electrotypes of figures 
Nos. Ill and 361. 

Dr. J. A. Lintner, State Entomologist of New York, kindly 
supplied an electrotype of figure No. 282. 

Prof S. A. Forbes was equally courteous concerning figure 
No. 187. 



A CKNO WLED G ME NTS. 



ix 



Prof. C. P. Gillette loaned for reproduction figure No. 150. 
Mr. Frank Sempers, of Philadelphia, kindly gave figure No. 
49- 

Mr. H. G. Hubbard, of Washington, obligingly loaned figure 
No. 359. 

Of the machinery illustrated, an electrotype of No. 476 was 
supplied by Mr. McGowen, of 478 by Mr. William Stahl, and 
of 479 by W. & B. Douglas. 

The following are originals, and were especially prepared for 
this work: Nos. 2, 3, 8, 9, 18, 19, 20, 21, 24, 25, 54, 57, 63, 
66, 67, 69. 113, 126, 135, 153, 154, 155, 184, 185, 215, 248, 249, 
250, 251, 252, 257, 266, 267, 272, 285, 304, 305, 306, 322, 323, 
344, 345> 346, 348, 379, 41 5, 43^, 453, 477- Of these original 
figures, some are photographs, others are from drawings by the 
author, some are redrawn, and a few are duplications of published 
figures where no plates were known to be in existence. 

To all who have in any way aided in the preparation of this 
work, and especially to Mr. L. O. Howard, of Washington, who 
kindly read my chapter on Hymenoptera, and Prof Lawrence 
Bruner, who kindly read my chapter on Orthoptera, I tender 
my sincere thanks. 



INTRODUCTORY. 



Insect injury to agricultural products amounts each year to 
millions of dollars, and, as a whole, shows a tendency to increase 
rather than otherwise. It is not only the actual devouring of 
plant tissue that causes loss ; the effect upon the product may 
be to reduce its grade, or make it more or less unsalable and 
unprofitable. In the competition for markets, the grower of 
the best will always have an advantage ; first-class fruits and 
vegetables rarely fail to bring some profit, where low-grade 
products cannot be sold at any price ; and no fruit that is 
wormy, defaced, or otherwise injured by insects ever ranks as 
first-class. 

Progressive farmers have long been aware of this, and the 
science of economic entomology has grown up in response to 
their demands for information concerning insect depredation and 
for means of protection against it. It is a science far from sys- 
tematized as yet ; made up of fragments published here, there, 
and everywhere, rarely complete in themselves and often con- 
tradictory as to the remedial measures suggested. There have 
been efforts, more or less successful, to compile books of infor- 
mation concerning the insects attacking certain crops or kinds 
of crops ; but there is not now in existence any work which 
gives the agriculturist and student of economic entomology that 
basic knowledge that enables him to recognize the nature of the 
insect he finds causing injury, or makes it possible to decide 
what sort of remedies should be applied. In other words, the 
underlying facts upon which the scientific application of remedial 
or preventive measures is based are not accessible to the very 
class that most needs them. 

In this book an attempt is made to present these matters com- 
pletely enough to give a foundation upon which further informa- 
tion may be added ; for whatever changes may occur in our 

XI 



xii 



INTRODUCTORY. 



battery of insecticides, the philosophy of their appHcation will 
remain the same. To do this it is necessary to give an outline 
of the characteristics of insects generally ; of those features that 
distinguish them from all other animals, and of those pecuHarities 
upon which we must base our hope of conquering them. Enough 
of the structure is described to show how they are built up, and 
all the different orders are referred to, so that the intelligent 
reader may recognize at least the group to which a specimen 
belongs and may be able to determine whether or not an injurious 
species is in hand. The direct needs of the agriculturist have 
been kept constantly in mind ; but the effort has been to give 
also a general information on the subject of insect life, and the 
work should be useful to students in all save advanced college 
courses, where technical or systematic studies outrank all others. 



AN ECONOMIC ENTOMOLOGY. 



PART I. 
STRUCTURE AND CLASSIFICATION. 



CHAPTER L 

THE GENERAL STRUCTURE OF INSECTS. 

Insects are animals made up of a series of rings or segments 
stiffened by a hard substance called chitine, and connected by a 
membrane which allows of more or less freedom of motion be- 
tween them in one or more directions. In this they agree with 
the worms, differing from them, however, in the adult stage, in 
that the segments are grouped into three regions ; the head, 
thorax, and abdomen, as shown in the diagrammatic sketch of 
the grasshopper. In the larval stage of many insects these re- 
gions are not well marked, and they resemble worms decidedly, 
but nearly always have a distinct head and more or less distinct 
legs. If neither head nor legs are visible, the larvae are chunky 
and maggot-like or grub-like, rarely long and cyHndrical. In 
fact, we have very few terrestrial worms in our country, and 
most of the so-called * ' worms ' ' are really insect larvae. 

As a rule, an insect is made up of thirteen rings, counting the 
head, and in the larval stage they are usually easy to make out, 
especially in caterpillars, which may be abundantly secured at any 
time during the summer. In the adult they are often more or 
less obscure. Following the head we have three segments which 
form the thorax or trunk, and these bear all the organs of loco- 
motion in the adult. In the larva, when organs of locomotion 
are present, one pair of legs is found on each of these segments. 

II 



12 



ajv economic entomology. 



Nine rings are assigned to the abdomen, though some of them 
may be modified into structures faciUtating egg-laying or other 
special purposes. In the adult no appendages of any kind, ex- 
cept ovipositors, anal filaments, or cerci, are found ; but in the 
larva, where there is often no real separation between thorax and 
abdomen, the latter may bear organs of locomotion which differ 
in their general appearance and structure from the true legs, and 
are therefore called "false feet," or pro-legs. The number of 
these pro-legs sometimes enables us to recognize the order to 
which a larva belongs, where it otherwise closely resembles 
another. For instance, all the true caterpillars are larvae of 
Lepidopte7'a^ or butterflies and moths, and these never have 
more than four pairs of pro-legs at the middle of the body and 
one pair on the last segment, making, with the true legs, eight 
pairs in all. In the larvae of the sawflies, a family of the Hy7nen- 
optera in which the resemblance to caterpillars is very close, there 
are at least five pairs of pro-legs at the middle and one pair at 
the end of the body, or no less than nine pairs of legs instead 
of eight as before. 

No insect has more than two pairs of wings, and these are 
attached to the second and third thoracic segment. Some have 
only a single pair, as in the true flies, and then they are on the 
second or intermediate segment. The prothorax. or first seg- 
ment, never bears wings. Each thoracic segment bears a pair of 
legs, which are themselves divided into joints or segments, and 
their structure will be described more in detail later on. 

This division into three distinct regions and the limitation to 
six legs in the adult separate the insects from crustaceans, like 
lobsters, crabs, shrimps, and the like, and from the spiders ; none 
of which have the head separate from the thorax, while all have 
eight legs instead of six. An insect in the adult stage is there- 
fore a jointed animal, the rings, thirteen in number, separated 
into a head of one, a thorax of three, and an abdomen of nine 
segments ; moving by means of three pairs of jointed legs. Some 
diflerences between "larva" and "adult" have been spoken of, 
and it has been indicated thereby that at different periods of 
their lives insects are unlike in appearance. This branch of the 
subject is exceedingly interesting, and will be treated more fully 
in Chapter VIII. It is only necessary to say here that, in speak- 



14 ECONOMIC ENTOMOLOGY. 

ing of the difference between larva and adult, reference is particu- 
larly made to those forms in which the two stages are totally 
unlike each other in appearance. Some of them resemble each 
other throughout their entire life, and here the term "nymph" 
is often employed instead of larva. 

It remains to say a few words concerning the chitine, which 
forms so large a part of the outer skeleton or crust. This sub- 
stance is found in insects and in certain of 
the crustaceans, and is a flaky, horny, or 
shell-like material which may become very 
hard, and is impenetrable to most Hquids 
not absolutely corrosive in character. The 
importance of this fact it is necessary to 
recognize in our selection of insecticides, 
because nothing that we can apply with any 
safety to the plant is sufficiently active to eat 
through or penetrate the outer skin into the 
insect body except under peculiarly favorable circumstances. 
None of the oils penetrate it readily, even gasoline, benzine, or 
kerosene being resisted. Alcohol, chloroform, and ether are also 
unable to make their way through any but a very thin coating. 



CHAPTER II. 

THE HEAD AND ITS APPENDAGES. 

The head of an insect bears structures of great interest from 
the economic stand-point, and of these the mouth parts are the 
most important. In most cases a glance at the structure of the 
mouth gives a clue to the food habits of the species, and may 
convict a culprit whose work has been discovered, or determine 
the character of the remedy to be applied. 

Roughly speaking, two types of mouth structure are found in 
insects, — the biting or mandibulate, and the sucking or haustel- 
late ; though there are modifications of both which are somewhat 
intermediate in character. 

In the typical "mandibulate" or biting mouth, the mandibles 



Fig. 2. 




Section through insect 
crust, showing layers of 
chitine at c, the cellular 
layer or hypodermis at 
}iy and basal membrane 
at b. 



STRUCTURE AXD CLASSIFICATION. 



15 



Fig 



or upper jaws are distinct and prominent. They work horizon- 
tally, from side to side, instead of vertically, or up and down, as is 
the case in the higher animals, and their form and general shape 
often furnish an indication to the character of the species, — that is, 
whether it is predace- 
ous, living upon ani- 
mal food, or whether 
it is phytophagous, 
feeding upon plant 
tissue. This alone, in 
some orders, suffices 
to tell us whether we 
have to deal with a 
friend or an enemy. 
If the jaws are rather 
long, sharp-pointed, 
with slender, sharp 
teeth on the inner side 
(Fig. 3, c, d), it may 
be safely classed as 
predaceous ; if they 
are broad, stout, con- 
cave within, the edges 
meeting broadly, even 
if toothed, or if they 
are gouge-shaped 
(Fig. 3, a, e), we can 
say with great confi- 
dence that the species feed upon vegetable tissue. Of course 
some uncertainty may result in intermediate types (Fig. 3, b) ; 
but the rule holds good generally, and where it leaves a doubt, 
some other character will readily determine the question. 

Formiing the front of the mouth and covering the base of the 
mandibles is the upper lip, or labrum ; on the inner side of which 
there is usually a sensitive structure, the epipharynx, which con- 
tains the organs of taste, and corresponds as nearly as may be to 
the palate in higher animals. It has no special function in feed- 
ing, and often seems to form part of the front of the head itself 

Below the mandibles we have a second pair of jaws or 77iaxillce^ 




Mouth parts of a mandibulate insect : different types 
of mandibles at a, b, c, d, e ; f, the labrum-epipharynx ; 
g, k, types of maxillge ; the cardo at c ; stipes, st ; sub- 
galea,^^-; galea as marked ; palpus bearer, //r; palpus 
2Xmxp; lacinia at/ac; and digitus at ^f?^ ,■ z, the labium 
with sub-mentum, S7n, mentum, m, ligula, lig, para- 
glossa,/>ar, and palpi. 



i6 



AJV ECONOMIC ENTOMOLOGY. 



much more complicated in structure, and made up of a number 
of more or less well-marked smaller pieces, which vary consider- 
ably in form and shape according to the food habits of the insect. 
Attached to each maxilla is a palpus^ or feeler, which often bears 
organs of special sense, and is probably used by the insect to 
recognize the character of its food. In function this maxilla is 
auxiliary to the mandibles, which cut and tear the food, and de- 
liver it in coarse shape to the maxillae. These assort and break 
it up yet more to better its mechanical condition, and deliver it 
to the labium, or lower lip, which also takes part in mixing the 
food. There are great differences in this maxillary structure, 
corresponding to the food habits ; and there may be teeth, 
brushes, or other appendages suited to the requirements of the 
insect. It is rarely necessary to study these in detail, and Fig. 3 
illustrates sufficiently a typical form, with all the parts named. 

The labium, or lower lip, closes the mouth opening beneath, 
forming its floor, on which is another sensitive surface, the hypo- 
pharynx, which may be compared in function to the tongue of 
the higher animals. As a rule, this labium is much less complex 
than the maxilla, and it may be only a single piece or plate, 
though, like the maxilla, furnished with a pair of palpi or feelers. 
A typical labium is shown at Fig. 3, and the names of the parts 
are given. Close study shows that originally the labium was 
made up of just as many parts as the maxilla, but they have 
grown together, in the course of time, for the more complete 
closure of the- mouth opening. 

Insects with the mouth as above described, no matter what 
their feeding habits, are always susceptible of being poisoned 
through their food ; that is, they may be reached by means 
of stomach poisons. Sometimes, of course, they feed in such 
positions that we cannot apply the poison satisfactorily, — e.g., 
inside of plant tissue ; but this does not alter their susceptibility ; 
it simply means that we cannot take advantage of it. 

Of the haustellate or sucking mouth there are several varieties, 
functionally quite diverse and indicating difference in habit. 

Butterflies and moths differ from all other insects in having the 
mouth formed into a flexible tube, coiled like a watch-spring 
under the head and between the labial palpi, which are the only 
visible mouth appendages present. The mandibles have disap- 



STRUCTURE AXD CLASSIFICATION. 



peared entirely, and all the other structures have been so modi- 
fied that nothing remains except this flexible sucking tube. I 
use the term "tube," although it is not such in reality, being 
made up of two hollow crescents, more or less firmly held to- 
gether, so that, practically, it serves all the purposes of a complete 
tube. When the insect feeds the tongue is extended, the muscu- 
lar structure being accommodated in the walls of each half of the 
tube. Fig. 4 illustrates a section through a butterfly tongue, 
showing the way in 
which the two parts 
are united. At its 
tip there are often 
more or less devel- 
oped processes which 
serve as taste cups, 
and also to assist in 
gathering up the 
minute globules of 
nectar. 

A tongue of this 
description indicates a type which can never be harmful to vege- 
tation, because it is not fitted for either piercing or eating plant 
tissue ; but it is, on the contrary, of direct use in pollenizing 
flowers. Butterflies and moths are never injurious in the adult 
stage, however much their larvae may offend ; but many are 
especially adapted for pollenizing certain flowers. Thus the 
" Hawk-moths," with tongues five and six inches in length, are 
able to reach to the very base of flowers like the petunias, even- 
ing primrose, " Jimpson weed," and many orchids. 

A widely different type of sucking mouth is found among the 
"bugs," or Heiniptera. Here, instead of a flexible tube, there 
is a jointed, rigid beak or rostrum, made up of either three or 
four segments, inside of which run four pointed lancets. This 
beak is not a complete tube, but narrowly open in front and at 
the tip, to permit the protrusion of the lancets. Insects with this 
structure gain their food by piercing the plant tissue and sucking 
the juices, and such a structure always leaves its possessor open 
to the suspicion of being injurious. As a matter of fact, many of 
the Hemiptera are really predaceous upon other insects ; but, as 



Fig. 4. 




Section through a butterfly tongue. 



i8 



AN ECONOMIC ENTOMOLOGY. 



Fig. 5- 



a rule, they will bear close watching. One thing is certain, how- 
ever : no insect with this type of mouth structure can be reached 
by means of a stomach poison. Destruction through its food is, 

therefore, absolutely impossi- 
ble, because we cannot poison 
the plant juices by any method 
thus far at our command. An 
insect of this kind is incapable 
of eating any solid food what- 
ever, and no matter how thor- 
oughly covered with a corro- 
sive poison the outside of our 
plants may be, it would get 
none, since it only punctures 
the tissue without absorbing 
any portion of the outer sur- 
face. Thus the determination 
of the type of mouth structure 
often limits or decides the char- 
acter of the remedy to be used 
in destroying the insect. 

Among the Diptera, or flies, 
we have a number of interest- 
Mouth parts of a plant-louse.— a, the ing modifications of the suck- 

jointed beak ; the lancets, much enlarged ; Jj^^r niouth. One SCrieS is fur- 
c and d illustrate the feeler and foot. , . * , 

nished with lancets similar to 
those in the bugs, but more numerous, representing different 
mouth structures, and not always carried into the head itself. 
The sucking structure is also quite different, and never forms a 
rigid, jointed beak. Mosquitoes and horse-flies are examples of 
this kind ; but gradually the lancets disappear, and in most of the 
flies only the sucking lip, often greatly and interestingly developed, 
remains. The common house-flies and blow-flies are types of this 
modified form, and are capable of taking liquid food only, though 
often seen attacking soHds. If the mouth of a fly be examined 
under the microscope, there will be seen at the tip of the lip a 
series of deep grooves, stiffened with chitinous loops, and armed 
with sharp projecting edges. When the fly wishes to feed on a 
solid, it scrapes the surface by means of these rasp-like projec- 




STRUCTURE AND CLASSIFICATION. ' 19 



Fig. 6. 




tions, securing a small amount of fine shreds and scraps. These it 
moistens with a drop of saliva, which has great solvent properties, 
and then draws up the mixture by means of a sucking or pump- 
ing stomach. Liquids are taken in the same way, and the insects 
may be said to lap as well as suck their food. Flies as adults are 
not injurious to vegeta- 
tion, whatever may be 
said of their larvae ; but 
some of those fitted for 
piercing, like the mos- 
quitoes, horse-flies, and 
gnats, are often trouble- 
some or injurious to 
stock, and occasionally 
render regions infested 
by them scarcely habit- 
able for man. 

The bees seem to 
combine the features of ^. . ^ r «u ,, u 

Piercing mouth structures of a horse-ny : the 
a biting and sucking sucking Hp is omitted. Much enlarged. 

mouth ; the mandibles 

being fully developed and the labium greatly elongated, that they 
may gather the nectar upon which they feed and which they 
store, even from the deepest flowers. This modification will be 
more fully described in speaking of the bees themselves. 

All the types of mouth structures above described and figured 
are derived from one original form by gradual modifications of 
the different pieces ; but this can be traced only in a long series 
of preparations from many different families and species. 

Next to the mouth parts, the most important appendages of 
the head are the antennae or feelers. These are variable in form, 
and in certain orders their structure indicates, unfailingly, the 
food habits of the insect. They are made up of a variable num- 
ber of joints, differing greatly in their proportion to each other, 
in their shape, and in their functions. Ordinarily the antennae 
are intended as tactile organs, — that is, for touching, as the com- 
mon name "feeler" indicates; but it is very certain that other 
sensory structures are also located there. The perception of 
odors, or the sense of smell, is a very important function, and 



20 



AA^ ECONOMIC ENTOMOLOGY. 



more than likely there is also a sense of hearing connected with 
them. In some of the nocturnal moths they are broadly feath- 
ered or pectinated, much more prominently in the male than in 
the female. It is believed that the reason for this is that the 
insects are compelled to find their mates entirely by the sense of 



Fig 




Tip of the mouth of a lapping fly, showing the pseudo-trachea on the inner face of the 
lips. Much enlarged. 

smell. That it is not food they seek is proved by the fact that 
where these feelers are most developed the mouth parts are often 
entirely aborted and the insect takes no food at all. Certain 
" carrion beetles," also nocturnal in habit, are attracted for long 
distances to their food, and, even where purposely hidden, they 
find it without difficulty ; proving that the sense of smell alone is 
used. It may be convenient to consider here a few of the com- 



STRUCTURE AND CLASSIFICATION. 



21 



mon types of antennal structure, which occur in all insects, that 
they may be referred to hereafter without especial description. 

The antennae are said to be filiform, or thread-like, when the 
joints are nearly even throughout, cylindrical, tolerably equal in 
length, and similar in general appearance. A serrate or saw- 
toothed antenna has the joints more or less triangular in shape 
and so fitted that one margin resembles the toothed edge of a 
saw. Quite frequently antennae of this type are distinctly flat- 
tened. From such a serrated form we pass gradually into the 



Fig. 8. 




Antennal types. — a, filiform and pubescent; b, serrate; c, singly pectinate; d, bipecti- 
nate; e, clavate ; /, capitate; g, geniculate; h, lamellate. 

pectinated or comb-toothed type, where the joints are furnished 
laterally with processes of variable length. When both sides of 
the joints have these processes the antenna is said to be bzpec- 
ti7iated or feathered ; when the processes become very slender, 
almost hair-like, and exceedingly numerous, it is said to be 
plumose. A feeler is clubbed, or clavate, when the joints toward 
or at the tip suddenly or gradually enlarge to form a more or 
less evident club or bulb, and this type is widely distributed in 
all the orders, a variety of terms being in use to indicate the 
particular form of the club. A lamellate feeler has at its tip a 
series of elongate, flattened or leaf-like joints, usually applied 
close together to form a solid mass that conceals and protects 



22 



AN ECONOMIC ENTOMOLOGY. 



the delicate sensory structure on the inner surface. An antenna 
is moniliform, or bead-Hke, when the joints are more or less 
spherical and set together in such a way as to resemble a series 
of beads on a string. 

As a rule, the antennae are straight, without break from base 
to tip ; but occasionally they are geniculate^ or elbowed ; that is to 



Antennal types: fl, moniliform ; joints ciliated; brum; rf, mandibles; ^, ocelli ; y, place 
c, bristle-tufted ; d, plumose ; e, setaceous. where antennae are inserted. 



segments set in at right angles to it. Usually an elbowed an- 
tenna is also clubbed at the tip, and so we divide the structure 
into "a scape" at the base, the "club" at the tip, and the 

funicle" embracing the intervening portion. 

The feelers may be clothed with fine, soft, more or less dense 
hair, and are then pubesceyit ; or furnished with lateral hairs of 
moderate length set in regularly, and are then ciliated or fringed ; 
or they may have single or bunches of stiff bristly hair, and are 
then said to be bristled, or bristle tufted. 

These are all the movable appendages of the head, and there 
remain only the organs of sight, which are perhaps better con- 
sidered under the heading of sense organs. It is only necessary 
to say here that the compound eyes are often very prominently 
developed, and that they are usually set at the sides, often form- 
ing the greater portion of the head itself The ocelH, on the 
other hand, are always very small structures ; in the adults, never 
more than three in number, and quite variably arranged. 




Fig. 9. 



say, there is one very long 
basal joint, the "scape," fol- 
lowed by a series of smaller 



STRUCTURE AND CLASSIFICATION. 



23 



CHAPTER III. 

THORAX AND ABDOMEN. 

The thorax, or middle region of the body, is, as has been 
already stated, composed of three rings, termed in their order 
the pro-, meso-, and metathorax ; meaning fore, middle, and 
hind thorax. These rings vary greatly in their proportion to 
each other : it is rare that they are equally well developed, and 
whenever this is the case it indicates a low type of insect, — that 
is to say, one very little specialized. Usually they are grown 
together to some extent, and this tendency continues until we 
find in the flies and bees the entire thoracic region apparently 
composed of one solid mass, — the rings being not at all movable 
upon each other. Insects of this type are highest in the scale 
and the most speciaHzed. In other orders, notably the Coleop- 
tera, or beetles, the prothorax only is free and well developed, 
the two other rings being united together and not movable one 
upon the other. This forms a sort of intermediate type, and the 
rank of insects is determined, to some extent, by the development 
of this region of the body. 

If the thorax of a grasshopper, a bettle, or a wasp be rather 
closely examined, it will be found that it is made up of a large 
number of little pieces, divided by impressed lines, and sometimes 
these pieces are movable one upon the other. They are called 
sclerites, and a sclerite, whenever that term is used, always 
means a solid piece bounded by impressed lines, or sutures^ as 
they are termed. Perhaps ' ' seams ' ' better represents the actual 
case than "lines," because they mark the places where pieces 
have been joined together, even if the joint be now a solid one. 
Though these pieces seem confused at first sight, yet there is a 
distinct plan in their arrangement, and, while it is not necessary 
to go much into detail, it is well to know at least the regions 
of the segments and the terms applied to them. In Fig. 11 
will be found an illustration of the under side of a beetle, in 
which all the sclerites of that part of the body are named. Those 
who wish a more accurate knowledge can compare a series of 



AN ECONOMIC ENTOMOLOGY. 



Fig. II. 




A beetle, Harpalus caliginosus, from the under side, with all the pieces named. 



STRUCTURE AND CLASSIFTCATION. 



25 



insects with this figure, and by identifying the different pieces 
observe for themelves what modifications have taken place. The 
upper side is ahvays called the dorsum, or dorsal surface, while 
the under side, between the legs, is the sternum, or breast. 
Laterally, between the sternum and the dorsum we find the 
pleurion, which is a region rarely referred to in general descrip- 
tion. The "dorsum," " dorsal surface," and "sternum," on the 
other hand, are terms of frequent occurrence in the literature of 
economic entomology, and it is well to know exactly what is 
meant by them. 

As has been previously said, all the organs of locomotion in 
the adult insect are attached to the thoracic segments ; never 
more than three pairs of legs, one pair to each segment, and 
usually two pairs of wings, borne on the meso- and metathorax. 
The prothorax never bears wings, and, when only a single pair 
is present, as occurs normally in the flies, or Diptera, this is on 
the meso- or middle thoracic segment. 

Of the wdngs, or organs of flight, all that need be said here 
is, that they are more or less membranous, flattened, and stiff- 
ened by " veins" or chitinous rods. They vary greatly in char- 
acter, and must be especially described for each order, their 
general structure being all that it is necessary to give here. In 
their origin wings are merely collapsed sacs, — that is, each is a 
bladder-like outgrowth from the body wall, that assumes definite 
form, but remains filled with liquid until ready to assume its final 
shape. Then it is gradually distended to full size, the liquid is 
absorbed, and the walls of the bladder unite and become so 
closely welded together that it is impossible afterward to separate 
them. The wing seems like a single thin membrane, or horny 
shell, as the case may be, and the veins appear like hollow rods 
or cylinders, though originally they were mere thickened grooves 
on opposite sides of the distended bladder. The arrangement of 
the veins, or "venation," is of very great importance in classifi- 
cation, but needs no particular exposition here. 

The legs, always six in number in the adult, are jointed, or 
made up of a definite number of parts or pieces. They are fixed 
into the thorax at the sides of the sternum, or between the breast 
and the sides, and are fitted into a body cavity by means of a 
ball-and-socket joint, giving a great range of motion. The ball 



26 



AN ECONOMIC ENTOMOLOGY. 



portion belongs to the leg and is called a " coxa," and the socket 
is the " coxal cavity." Attached to the coxa is the "femur," 
or thigh, usually the stoutest part of the leg, and corresponding 
to the same portion of the leg in the higher animals, most of the 
muscular system being found in it. It is often strengthened at 
the base by a small supplementary piece called the "trochan- 
ter," which sometimes forms an intermediate segment between 
coxa and femur, and may be even two-jointed, as in the parasitic 
Hymenoptera. At the end of the femur is attached the "tibia," 
or shank, which varies greatly in structure according to the 
habits of the insect, being modified for digging, tearing, swim- 
ming, clasping, or other special functions. It is armed in many 
ways, and becomes an index to the life history of the insect, 
furnishing, also, many good characters of use in classification. 
Economically, it is useful in that it is a guide from which we can 
often get an idea of the kind of existence that the insect leads, — 
whether it is a digger, a swimmer, or a carnivorous type. The 
terminal part of the leg is the "tarsus," or foot, and this is also 
jointed, —five joints being usual, though variations frequently 
occur. The last joint is armed with a pair of claws, and between 
them we may have "pulvilli," or small pad-like structures, by 
means of which flies and other insects cling to smooth surfaces 
and are able to walk back downward on ceilings. The differ- 
ences in the leg structure are easily seen with a little experience, 
and in some orders, notably the Coleoptera, they serve to divide 
the insects into large groups or series. 

The abdomen normally contains nine segments, but these are 
rarely all distinct. As a rule, one or more are modified to form 
sexual organs or appendages, or shields, or other accessory 
structures. It sometimes happens that the segments on the 
dorsal, or upper, and ventral, or under, side do not correspond, 
one part of the ring being lost or modified. In the adult the ab- 
domen never bears organs of locomotion, and, as a rule, no appen- 
dages of any kind, except an ovipositor in the female of certain 
groups, or a pair of claspers in the male. In some of the lower 
orders it bears jointed filaments or appendages resembling feelers, 
and these are called " cerci." Only in the lowest of all types do 
we find traces of rudimentary legs on the abdominal segments, 
indicating a relationship between the insects and myriapods. 



STRUCTURE AND CLASSIFICATION. 



27 



CHAPTER IV. 

MUSCLES, DIGESTION, AND CIRCULATION. 

Insects have no internal skeleton or bony structure, the body 
wall serving for the attachment of muscles and to protect the 
inner organs. 

Cutting transversely through the thorax of an insect at its mid- 
dle, we find the greatest portion of the body cavity occupied by 
muscles, which are arranged in bundles attached to the entire 
inner surface of the body wall, proceeding to all the appendages, 
and thus providing the power that moves the animal. Centrally, 
the alimentary canal occupies a part of the body cavity, its size 



Fig. 12. 




Ideal section through an insect.— a, alimentary canal; A, heart; «, nerve-cord; s, stig- 
mata ; t, tracheal tubes ; /, legs ; w, wings. 

depending considerably upon the kind of insect in hand. Just 
below the dorsal surface is a small tubular structure, at once the 
heart and only blood-vessel, while just above the ventral surface 
is a white, knotted cord, — the nervous system. Laterally, there 
is an opening on each side, from which a ringed tube leads into 
the body, dividing and subdividing almost immediately into 
innumerable branches, and this is the respiratory or breathing 
system. Frequently we find around the alimentary canal a con- 
siderable fatty mass, while everywhere through the insect body 



28 



AN ECONOMIC ENTOMOLOGY. 



we meet with a whitish or slightly greenish liquid, much more 
abundant in the larva than in the adult ; and this is the blood. 
These various systems are of economic importance, for upon 
our full understanding of some of them depends the success with 
which we can apply insecticides of a certain character. 

Perhaps the least important in this view is the muscular sys- 
tem. It has been stated that the muscles are found in the form 
of bands, which extend from the body walls to the various ap- 
pendages, and, of course, they are numerous and strong in pro- 
portion to the power required. Thus, for a leaping insect the 
muscles moving the legs are very much more developed than 
they are in an insect which simply walks or runs, and in a run- 
ning insect they are better developed than in one that simply 
walks or moves slowly. Where powerful appendages must be 
moved, as for instance the mandibles or jaws, several bundles 
of muscles frequently converge to a chitinous point or tendon, 
which in turn is attached to the appendage, and thus a great 
amount of force is exerted at one point, the muscular attach- 
ments on the body wall covering a considerable surface and con- 
verging all their effectiveness upon one lever only. It is this 
arrangement that gives some insects the gnawing power to bur- 
row in the hardest woods, and to cut through foreign substances, 
like lead, in order to escape from captivity. 

Under the microscope it is found that the ultimate structure of 
insect muscle does not differ in essentials from that of the higher 
animals ; that is to say, it is made up of narrow fibres divided 
into cells, and transversely striated. The voluntary muscles of 
insects are, therefore, practically like the voluntary muscles of 
the higher animals or of men. 

The digestive system is of much more importance from the 
economic stand-point. On a previous page it has been shown 
that two general types of feeding habits exist, the chewing and 
the sucking, and the digestive system changes somewhat as the 
needs of the organism vary. The mandibulate type, in which 
the insect chews its food and subsists upon more or less sohd 
material, will be first considered. Most insects in the larval stage, 
and sometimes also as adults, are voracious feeders, seeming 
determined to devour as much as they can possibly contain, in 
the shortest possible time ; and the food is in such cases rather 



Fig. 13. 




Mandible of a carpenter-bee, with bundles of muscular fibres attached, each bundle 
converging to a tendon, and the latter attached to a mandibular process. 



STRUCTURE AND CLASSIFICATION. 



29 



Fig. 14. 




Digestive systems : of a katydid, at a / of a grasshopper, at b ; and of a roach, at c. All 
the parts are named save the thread-like Malpighian tubules. 



30 



AN ECONOMIC ENTOMOLOGY. 



coarsely ground up by the mouth parts, and forced through the 
gullet or oesophagus into the crop. The oesophagus is simply a 
slender tube, usually straight or only a little bent, at the mouth 
of which salivary glands open, and the food, mixed with saliva, 
passes through it into the crop. This crop is a more or less 
muscular, but always distensible sac, and usually the largest 
single organ in the body. It is used, primarily, as a place to 
store food when the insect has the opportunity of obtaining it, 
and is capable of containing a comparatively enormous amount 
of material. At its posterior end it opens into a gizzard, or 
grinding stomach, and this receives the food in small quantities, 
to be further reduced and put into better mechanical condition 
for assimilation. For this purpose it is armed with a complicated 
set of plates and teeth, not alike in any two species, while its 
muscular coatings are dense and powerful, giving great twisting 
and grinding force. Sometimes the gizzard is well developed 
and prominent ; but often it is greatly reduced, appearing as 
little more than a slight specialization of the end of the crop. 
Its development depends very largely upon the character of the 
food and the feeding habits. Insects that eat indiscriminately all 
sorts of material, like roaches and crickets, have it best developed. 
From this gizzard the food, now in excellent mechanical con- 
dition, passes into the true stomach, or chyliftc ventricle, receiving 
at its mouth the secretions of the ccscal tubes or pouches. This 
secretion is digestive in character, like a similar liquid in higher 
animals, and assimilation begins in this part of the system. The 
stomach varies greatly in length in the different kinds of insects, 
and as much in relative size and the strength of its muscular 
coating. At its posterior end we find the long and slender Mal- 
pighian tubules, which often envelop the whole system in a ver- 
itable net-work of fine, thread-like masses. These structures are 
supposed to represent kidneys and to have a similar excretory 
function. They open at the junction of the stomach with the 
ileum, or small intestine, and in this the assimilation or absorption 
of food products is completed, the remnant being forced into the 
large intestine, or colon, where it is prepared for excretion through 
the rectum. A pair of glands near the end of the rectum secretes 
a mucus, probably intended as a lubricant only. 

The salivary glands vary in number, and one or more may be 



STRUCTURE A. YD CLASSIFICATION. 



31 



Fig. I 



modified for special purposes ; as in some of the piercing insects 
like bugs or the mosquitoes, where an irritant poison is secreted, 
or in certain beetles, where the saliva has 
both a staining and a burning effect upon 
the skin, or in many larv^ae, where the se- 
cretion forms a silk when hardened by ex- 
posure to the air. The anal glands may 
be similarly modified, but much more 
rarely than those at the anterior end of the 
body. In the "Bombardier beetle" their 
secretion volatilizes suddenly when expelled 
into the air, and forms a blue smoke, hke 
the discharge from a small cannon. In 
Hymenoptera, including bees and wasps, 
the secretion is poisonous, and accessory 
to the functions of the sting. More rarely 
a silk is produced from these glands. Taken 
altogether, the digestive system varies 
greatly in length, being sometimes a 
straight tube only, the various portions 
very incompletely divided off In other 
cases it is quite complex, coiled upon 
itself, the parts well defined, and the sys- 
tem as a whole two or three times the 
length of the entire insect, different kinds 
of structure being found in the various 
parts. The figures given herewith illustrate 
some of these differences. 

In the sucking or haustellate type the 
essential structure of the alimentary canal mandible of the same, 
and the differentiation of the parts are much °^ ^' 
the same. There is, however, a great reduction in the size of the 
gizzard, which is very often entirely wanting. If present, the 
. armature is reduced to a mere ridging, or a slight, irregular 
thickening of the walls of the posterior end of the crop. In the 
Lepidoptera there is often a peculiar accessory pouch, which 
seems to serve the purpose of a storage reservoir, or secondary 
crop, and this is attached by a narrow neck to the opening of the 
true crop. In the bees the crop is unusually elastic, and capable 




Salivary gland of the cat- 
erpillar of Melittia ceto, 
modified for silk spinning : 



32 



AN ECONOMIC ENTOMOLOGY. 



of enormous distention compared with the size of the insect, and 
this is to accommodate the honey collected by the insects to be 
carried into the hive. 

In the use of poisons acting through the stomach, the arsenic, 
which is usually employed, is taken in with the food and gener- 
ally carried into the chylific ventricle before it becomes effective. 
In the crop the food is generally too dry to cause the necessary 
solution of the caustic properties of the arsenic, which is neces- 
sarily applied in its least soluble form ; but by the time it has 
passed through the gizzard and has reached the stomach, becom- 
ing moistened and mixed with the secretions that have been 
already mentioned, it becomes active. Some insects are able to 
take a very large quantity of poisonous material without injury ; 
succumbing only after two or three days to the effects of a poi- 
sonous meal. It is probable that in such cases the digestive 
liquids exercise a less solvent effect upon the toxic mixture. 

Ordinarily, digestion in insects is exceedingly rapid. Among 
caterpillars, for instance, feeding is often almost continuous, and 
twenty-four hours are sufficient to pass through the entire diges- 
tive system food two or three times the weight of the larvae 
themselves. 

Fig. i6. 




Heart of a stag-beetle, showing the wings and chambers : at the side, the interior of a 
chamber, to show the valves. 

Insects have no system of arteries and veins, and only one real 
blood-vessel, which serves also as the heart. This, as has been 



STRUCTURE AND CLASSIFICATION. 



33 



indicated, lies just under the back, and in a cavity formed by a 
series of peculiar triangular muscles known as the ' ' wings of the 
heart ; ' ' and these serv^e to prevent undue pressure upon it. 
The organ is simply a long tube, open at both ends, and divided 
into a variable number of chambers, into which the blood is 
admitted at the sides, at intervals along its length. The heart- 
beat consists of a wave of contraction beginning at the posterior 
end, forcing the blood forward and out into the head. Some- 
times one wave is completed before another one starts, and 
sometimes two or even three waves may be on the road at one 
time. Sometimes the beat is exceedingly sluggish, and some- 
times, in active insects, it is very rapid. After the blood has 
been forced out of the heart it first bathes the head parts, and 
then makes its way between the muscles and other organs through 
the body cavity and into the appendages. Part of it bathes the 
alimentary canal, where it receives the products of digestion, and 
these are carried everywhere and assimilated by the various 
tissues, the blood eventually finding its way back to the heart, 
to begin its journey anew. The fact that there is no closed 
system of blood circulation is peculiar, and in this insects differ 
from all the higher animals. It necessitates a very decided 
modification of the respiratory or breathing system, and this 
forms the subject of the next chapter. 



CHAPTER V. 

THE RESPIRATORY SYSTEM. 

The respiratory or breathing system of insects is adapted to 
the system of blood circulation. It is important from the eco- 
nomic, as well as interesting from the scientific, stand-point, for 
upon this rests the basis for the application of contact insecticides. 
■ Insects have no lungs, and nothing which at all corresponds to 
them. They have no means of taking in air at the head or 
through the mouth ; but breathe from the sides, where there is a 
series of breathing-pores, or spiracles, through which the air is 
taken into the body cavity. Typically, one pair of spiracles 

3 



34 



AN ECONOMIC ENTOMOLOGY. 



occurs on each body segment ; but as a matter of fact some of 
the segments, especially in the adult, lose them, the insect de- 
pending upon a more limited number as the main trunks become 
enlarged. The insect blood requires oxygen, as in the higher 
animals, and, as there are no lungs to which the blood can be 
carried, it is necessary that the air itself should be taken to all 
parts of the body, and this is accomplished by means of tubes 
called trachecs. Trachea occur in insects, in spiders, and in 
myriapods, all of which are, therefore, called ' ' Tracheates. ' ' 
Spiders have eight legs instead of six as in the true insects, and 
have the head and thorax combined in one piece or cephalo- 
thorax. They have also a decided tendency to the formation of 
lung-sacs. The ''myriapods" or "centipedes" are more worm- 
like in structure, and are furnished with many legs, — one or two 
pairs on each body segment, — sometimes exceeding one hundred 
in number. 

One tracheal trunk or tube starts from each spiracle, and be- 
gins at once to divide and subdivide, sending its ramifications 
to all parts of the body, even to the tips of all appendages, so 
that air permeates every part of the insect, and tracheal tissue is 
present everywhere. The structure of these tubes is interesting : 
they consist of a membranous cylinder, stiffened by chitinous 
rings or spirals, in appearance very much like the closely-coiled 
springs in automatic shade-rollers. This gives rigidity to the 
tubes, keeping them always open, while at the same time it 
allows the utmost freedom of motion. A series of longitudinal 
tubes on each side of the body unite the main trunks from each 
spiracle, and in some cases there are transverse tubes joining 
the longitudinal tracheae. The entire system is thus connected 
in one or two ways, and at a pinch an insect is able to get its air 
supply from one spiracle only and from almost any part of its 
body. 

Where so many openings into the insect body exist there 
must, necessarily, be some arrangement for protecting them and 
preventing the entrance of foreign material. There is, therefore, 
a great variety of sifting structures, their character depending 
largely upon the habits of the insects. There may be a series 
of teeth or spurs on each side of a narrow, irregular slit ; a series 
of hairs or bristles crossing in front of the opening ; a covering 



STRUCTURE AND CLASSIFICATION. 



35 



Fig. 17. 




Tracheal tube, showing the structure and methods of branching. 

Fig. 18. 




Spiracles and their protection. — a, plate-like covering of white grubs, cross-sec- 
tioned at b, to show how air enters ; c, a toothed slit ; d, spiracle set on a teat-like 
process; e, conical spiracle set in a pit, protected by crossed hairs as shown at f in 
section ; g, lip-like spiracle ; h and z, unprotected round or slit-like openings. 



Fig. 19. 



Fig. 20. 





Tracheal gills.— a, leaf-like anal plate or 
Agrion ; b, thread-like tuft of Corydalus ; 
plate-like gill of Ephemera. 



Air-bladder at end of 
tracheal tube in Bom- 
bus. 



36 



AN ECONOMIC ENTOMOLOGY. 



shield, beneath which the air must enter, or some other variety 
of screen, — all intended to sift out of the air the foreign particles 
which might injure the insect. Yet it is through these spiracles 
that most of the contact insecticides must act, as will be more 
fully detailed hereafter. In many heavy insects there are at- 
tached to the tracheae numerous air-sacs or bladders, the object 
of which is to reduce the specific gravity of the insect to enable 
it to fly more readily. A common example is the well-known 
" May-beetle" or "June-bug," which has the entire body cavity 
filled with such little bladders. If one of these beetles be watched 
when it emerges from its hiding-place early in the evening, it 
will be noted that it first crawls to the top of some blade of grass 
or twig, or even upon a stone, and rests there a few minutes. 
If it be closely observed it will be seen to be pumping in air, — 
that is to say, the body pulsates rapidly, and the abdomen seems 
continually to increase in size. This is because the insect is fill- 
ing the air-bladders, and, as soon as this has been accomplished, 
it tries its wings, causing the preliminary "whirr" which is so 
familiar to the observer in the early evening of a June day. After 
two or three trials the insect becomes confident of its ability to 
sustain itself, and flies off heavily, with a steady hum. If such 
a beetle be found at mid-day and thrown into the air it will fall 
heavily, and will be absolutely unable to sustain itself in flight 
until it has had an opportunity to inflate its air-sacs. 

While the vast majority of ah insects are air-dwellers, yet many 
live underground, a very large number in water, and a consider- 
able percentage in decaying or excrementitious matter, vv'here 
pure air is very difficult or impossible to obtain. All sorts of 
devices to enable them to breathe under such conditions have 
been developed, and in all cases without any essential modifica- 
tion of the system. Underground dwellers usually find air suffi- 
cient for their needs in the earth in which they live, and the 
development here is principally in the direction of more perfect 
coverings for the spiracles to prevent the entrance of dirt. 

Among insects living in or under water, or spending a portion 
ol their life there, we note a great variety of modifications. 
Many beetles, and some insects of other orders, have the wing- 
covers dome-shaped, and so closely fitted that they are able to 
carry a little supply of air between them and the abdomen. 



STRUCTURE AND CLASSIFICATION. 



37 



When this supply is exhausted of oxygen, the insect rises to the 
surface, allows the drop of tainted air to escape, and at the same 
time takes in another bubble of pure air. It is then supplied for 
another period, varying in length in the different species. Cer- 
tain other forms have the body covered with very fine hair, so 
dense that the water cannot penetrate it, and these carry a thin 
film of air that surrounds them entirely while they are in the 
water ; they really do not get wet at all. This air supply must 
usually be renewed from time to time ; but occasionally oxygen 
is absorbed from the water itself, and the filmy covering is thus 
kept constantly purified. Yet other insects have their surface 
so absolutely smooth and polished that the water cannot touch 
it, and here also a slight film of air may be carried about. There 
are other devices to the same end, which it is needless to special- 
ize, and we pass to those insects that never come to the surface 
at all, and yet secure a sufficient supply of oxygen. These crea- 
tures are mostly larvae, and in them we note the development of 
structures resembling the gills of fishes in function. That is, in 
certain leaf-like or thread-like appendages there are a great num- 
ber of very fine tracheal tubes with very thin walls. Through 
them the insect absorbs the oxygen contained in the water itself, 
and we have exactly the same process that we find in the fishes, 
except that here air instead of blood is brought into contact with 
the oxygen in the water. These gill-like appendages vary greatly 
in number and shape, but do not differ in function, and will be 
further described when necessary in connection with the insects 
themselves. 

Yet another type of structure is found where the absolute con- 
nection with the air really never ceases, — that is to say, the in- 
sects have a rigid or an extensile tube attached to the anal end 
of the body, and this they keep pointing above the surface while 
they walk about on the bottom of the ponds. Insects so pro- 
vided are inhabitants of shallow water, and the tubes rarely ex- 
ceed an inch or an inch and a half in length. The common 
"rat-tailed larvae, " often found in the filthiest of all excrementi- 
tious material, are good examples of this method of breathing. 
They may be entirely imbedded in the pasty mass ; but the 
tip of the ' ' tail' ' is kept above the surface to enable them to 
secure fresh air. Finally, we have those cases where insects live 



38 



AJ^ ECONOMIC ENTOMOLOGY. 



in the water, yet get all their air from above it without any power 
of storing. This is the case with creatures hke the mosquito 
larvae, which are unable to breathe without coming to the surface. 
They have only a single spiracle at the tip of the body, and are 
compelled to rise to the surface at intervals to breathe, and, 
having done so, are able to sustain life beneath it for only a short 
time afterward. 

This much for the general characteristics of the respiratory 
system ; it remains to show how it is important from the eco- 
nomic stand-point. It has been previously said that the insect 
crust is of chitine, which is impervious to a great variety of 
ordinarily penetrating substances. It resists alcohol, chloroform, 
ether, the light mineral oils, benzine, turpentine, kerosene, and 
other similar substances ; acetic acid penetrates slowly and so 
does carbolic acid. This accounts for the difficulty which we 
find in destroying many insect eggs, for there are no openings in 
them that are sufficient for the penetration of these substances, 
and they are unable to act through the egg-wall itself To get a 
liquid insecticide to kill an insect by contact, it must be forced 
into the body through the spiracles, or they must be so gummed 
or clogged as to close them completely, thus preventing the in- 
sect from breathing at all. Kerosene is the most reliable of the 
penetrating liquids, and even where the spiracles are well pro- 
tected this material penetrates into the smallest openings. It 
has the advantage ol actually wetting everything ; that is to say, 
it is not repelled by small hairs, as globules of water would be, 
and therefore, as it really comes into direct contact with them, is 
enabled to work its way through the spiracles. That is what 
makes the kerosene so much better than any watery mixtures 
alone ; for whatever the material extracted by or dissolved in 
water, it may perhaps be repelled by the insect body, and never 
have the opportunity of exercising an effect. The various soaps 
act in another way ; as the moisture evaporates, a film of sticky 
or gummy material remains which clogs the spiracles, and thus 
chokes the insect by depriving it of air. Soapy mixtures also 
wet and stick well to insects through the caustics they contain, 
and which have the power of cutting the repellent material of 
their bodies. 

In some kinds of insects the spiracles are so feebly protected 



STRUCTURE AND CLASSIFICATION. 



39 



that dry insecticides penetrate them readily, if finely ground ; 
and all such are effective in proportion to their fine mechanical 
condition, enabling them to enter the tracheae through the sieve 
of the spiracles. Thus, sawfly larvae or " slugs," like the " cur- 
rant-worm" and " pear-slug," succumb readily to dry hellebore, 
pyrethrum, or even fine road dust. Many parasites may be 
reached in this way, and some animals and all fowls keep them- 
selves tolerably free from vermin by frequent dustings. This is 
not the place to go into the effectiveness of insecticides ; but it 
may be repeated that contact poisons usually act through the 
spiracles only. Dry powders are effective in proportion to their 
fineness and to their peculiar poisonous properties ; liquids are 
effective in proportion to the thoroughness with which they are 
applied, and to their penetrating or clogging characters. 

Caustics and chlorides act differently, and may actually corrode 
a thin insect crust. But this matter also comes more appro- 
priately under another heading, and will not be further discussed 
here. 



CHAPTER VI. 

NERVOUS SYSTEM AND SENSES OF INSECTS. 

The nervous system in insects consists of a series of white 
disks or gajiglia lying on the bottom of the body cavity, con- 
nected by a double cord extending the full length of the insect. 
Insects have no true brain, as do the higher animals, and the 
ganglion situated in the head, which is usually called " brain," is 
larger than the others simply because of the great number 
of special organs — eyes, antennae, and mouth parts — that must 
be innervated from it. In its structure it is precisely like the 
other ganglia, though in some of the social types there is an 
appearance of specialization. Nerve-fibres start from all ganglia 
in every direction, and all parts of the body are reached ; the 
nervous system in one direction being exceedingly well devel- 
oped. In the larval forms and in the lower types, a ganglion is 
present in every segment of the body, including the head ; and 
thus each segment contains its own nerve-centre, the cords from 



40 



A^' EC 0X0 MIC ENTOMOLOGY. 



which are primarily sent out to the organs and appendages Iving 
within that particular segment. In adults there is a tendencv 
to a union of the thoracic ganglia, and in the abdomen two are 
usually confluent toward the anal end of the body. The digestive 



tained in the head, may be entirely removed without necessarily 
killing the insect itself. 

While, as stated, the ner\^ous system is well developed and all 
the organs are well furnished with ner\-e endings, yet it is prob- 
able that insects are not particularly sensitive. The oft- cited 
case of the butterfly that was captured and pinned while alive, 
then escaped from the collector, and returned at once to its 
feeding among the flowers without apparent inconvenience, is 
known to most readers. If a dragon-fly be captured and held 
by the wings loosely, so as to prevent its escape but not to 
injure it, and the tip of its abdomen is then presented to its 
mouth, it proceeds at once to eat it as far as it can reach, with- 
out any apparent knowledge of what it is doing. It will thus 
devour, with the greatest portion of the abdomen, half its diges- 
tive system, nearly half its entire ner\'0us system, and a large 
part of its heart ; yet, if it be then released, it will fly oft' little 




Nervous system of the honey bee at c, and of its 
larva at b. 



Fig. 21. 



system is usually in- 
nervated by a spe- 
cial ganglion, and 
has its own. partly 
distinct system. In 
the higher insects the 
thoracic ganglion is 
the most important 
in the body for the 
life of the insect, and 
if this be cut or 
destroyed the insect 
dies at once. Any 
other ganglion may 
be cut without pro- 
ducing immediate 
death, and the brain, 
using that term for 
the gangHon con- 



STRUCTURE AND CLASSIFICATION. 



41 



the worse, except that it is unable to balance itself. Insects may 
lose a considerable number of their members without apparent 
inconvenience : a fly may lose a leg or two without seeming 
in the least worried, or one or both of its wings may be torn off 
without causing death or even a manifestation of pain. 

I once made a series of experiments to test, not so much the 
sensibility of flies, as the effect that cutting the various organs 
would exercise upon it. I found that if I cut off the abdomen 
completely, the fly would live for twenty-four hours thereafter ; 
with practically no digestive system, with very little nervous 
system, and with most of its heart gone. Turning the matter, I cut 
off the head, and found that it would live without a head for just 
about as long a time as it would without an abdomen. Of course 
death was bound to result from this mutilation in time, but the 
interesting feature is that no apparent symptom of pain was 
developed. I found, however, that just as soon as I cut the large 
ganglion in the middle of the thorax I terminated life. What- 
ever sentimental feeling there may be in the matter of causing 
unnecessary pain, there is no reason to believe that insects have 
any well-developed sensitiveness, as we understand that term. 
The character of the insect nervous system is so entirely different 
from our own that we are left without real guides in our interpre- 
tation of the various sensory structures. Man judges most things 
by himself, and where this guide fails he is at a loss, and cannot 
be certain that he interprets what he sees correctly. 

The eyes are perhaps the most prominent and best understood 
of the organs of special sense. They are of two kinds, simple 
and compound, and both may be present in the same species. 
The simple eyes are termed ocelli, and consist of a more or less 
convex, often bead-like lens or facet, by means of which an image 
is thrown on a retina, and thus transferred to the perceptive 
centres. In larvae simple eyes, or ocelli, are the rule, except in 
types with incomplete metamorphosis, where the eyes resemble 
those of the adults. In larvae the simple eyes may be situated at 
almost any point on the head ; but usually they are grouped at 
the sides : sometimes only a single ocellus at each side, sometimes 
a group of a dozen or more, forming the rudiments of a com- 
pound eye. In adults there are rarely more than three ocelli, 
usually situated in a triangle either close together or widely sep- 



42 



AA^ ECONOMIC ENTOMOLOGY. 



arated ; or there may be only two, one on each side, near the 
base of the antenna, as is usual in butterflies and moths. 



Fig. 22. 




Sensory organs of insects.— yi, one element in eye of a roach ; B, section of compound 
eye ; C, organs of smell in May-beetles ; D, sense organs in abdominal appendages ; E, 
sensory ear ; F, ear on foreleg of locust ; G, ear found on the basal segment of grass- 
hopper abdomen. All greatly enlarged. 



Compound eyes are so termed because they are made up of a 
great number of simple eyes, or ocelli, set very close together. 
If the head of a bee or house-fly is examined, it will be noted 
that the brown eyes occupy a very large portion of its surface, 
and if one of those eyes be viewed under the microscope it 
will be found to be faceted, or to consist of thousands of little 
hexagonal disks, resembling in appearance the top of a honey- 
comb. Each one of these facets represents a complete eye, 
capable of forming an image upon its own little retina, and the 
combination of all the little retinal pictures is what a fly or other 
insect sees. In some cases the eyes are so enormous that the 
insect can see everything going on in front, at each side, above 
and beneath, and even back, except directly behind it. It is 
difficult for us, who are able to see in one direction only, to 



STRUCTURE AND CLASSIFICATION. 



43 



imagine the sort of picture an insect perceives, and we are by no 
means certain how well or how poorly it really does see. We know 
only that larval forms and low types, provided with ocelli only, 
see very feebly and indefinitely, and can do little more than dis- 
criminate between light and darkness. Many insects have no eyes 
at all, living under such circumstances as to make them useless. 

That insects hear follows almost inevitably from the fact that 
many of them "sing," — that is, produce some sort of noise. 
What those organs of hearing are is not so certain in all cases, 
nor where they are situated, since we cannot confine our search 
for ears to the head alone. In the Orthoptera they have been 
located with a reasonable degree of certainty : in the grasshopper 
the ears are on each side of the basal segment of the abdomen, 
while in the locusts and crickets they are on the anterior tibiae. 
Essentially, these ears consist of a tense membrane stretched over 
a cavity, and connected by means of little processes, correspond- 
ing somewhat to the bones of the human ear, with a bulb-like 
vesicle and a large auditory nerve. In most other orders no 
similar structures are found, and the sense of hearing is located 
in the antennae, or feelers, of which more will be said later on. 

Insects are able to discriminate as between foods, and the sense 
of taste is undoubtedly developed to some extent ; but the taste 
which seems agreeable to their sense would be to us, in many 
instances, the vilest conceivable. No true tongue, as this organ 
exists in the vertebrates, is found among insects ; but on the up- 
per side of the lower lip there is often a finely papillate surface, set 
with little fleshy pegs and processes communicating with nerve 
fibres, and this represents the nearest approach to the tongue 
of the higher animals. It is called the hypopharyyix , and is 
not always present. Beneath the labrum, or upper lip, we often 
find a separate, flat, similar piece, and this is the epipharynx^ 
corresponding in function to the palate of the higher animals. 

Nothing resembling a nose is found among insects, and yet 
the sense of smell seems very highly developed. Insects often 
discover their food with unerring certainty, even when concealed 
from sight. Among the nocturnal species, where sight can play 
but a small part at best, the sense of smell seems most highly 
developed, and usually more in the male than in the female. 
This is due to the fact that the males, as a rule, seek their mates. 



44 



AN ECONOMIC ENTOMOLOGY. 



and so keen is this sense that they discover the presence of the 
female, even when confined in a breeding-cage, if a window be left 
open. Sometimes male wood-borers will sit around a spot on the 
bark for a considerable time awaiting the emergence of a female, 
which their keen sense tells them is fully developed and ready to 
make her way out. Carrion feeders discover their food when con- 
cealed from sight, and almost before decay has set in. So far as 
we have been able to ascertain, the olfactory organs are situated 
in the antennae, and form small pits or depressions, from which 
usually arise specialized hairs, bristles, or pegs, as the case may be. 



Fig. 23. 




Sensory organs of insects. — A, sensory pittings in plant-louse antennae; organ of 
smell in May-beetle; C, same in wasp; D, sensory organs in Termes flavipes ; E, F, 
organs of taste in a wasp ; G, organ of smell in grasshopper ; H, sensory depressions 
on the tibia of Termes ; I, terminal joint of antenna of an ant ; K, section through the 
antenna of a honey-bee, showing supposed olfactory- organs. All greatly enlarged. 



The sense of touch is located popularly, and I think correctly, in 
the antennae ; but it is quite certain that tactile hairs exist all o\-er 
the body of the insect, more developed in some than in others, 
and most, perhaps, in larval forms. These structures always 
consist of specialized hairs or bristles, and end in a nerve cell. 



STRUCTURE AND CLASSIFICATION. 



45 



It is probable that in the antennae we have a sense of percep- 
tion which is able to discriminate between atmospheric vibrations, 
and in this way the same or similar structures may serve as organs 
of hearing, smell, and touch. That is to say, it is probable that 
there is no such sense in insects as the power to discriminate 
between smells, but that each is able to recognize certain definite 
kinds of odors which do produce an effect upon it. So it is also 
likely that only sounds of certain descriptions are recognized, 
and these sounds may even be such as the human ear is not 
capable of perceiving. We are far from understanding the senses 
of insects, but the above outline is all that is necessary for our 
present purpose. 



CHAPTER VII. 

THE REPRODUCTIVE SYSTEM. 

The rate of increase among insects is often very great. It is 
nothing unusual to hear a farmer say that on one day his plants 
were free from insects, or nearly so, while a week thereafter 
everything seemed to be swarming. As a matter of fact, this is 
frequently due to a failure to observe the insects in the first place, 
either in the stage in which they then existed or on account of 
their small numbers ; but it remains true, nevertheless, that in- 
sects are often exceedingly prolific. The number of eggs laid 
by a female often runs up to one thousand, or even more, while 
the number of eggs within the power of a Termite queen is be- 
yond all calculation. If it were not for their natural checks, in- 
sects would soon overrun the world. In one year not one green 
thing would be left on the face of the earth, and not one living 
being other than insects would exist. These natural checks con- 
sist largely in sudden changes or abnormally high or low tem- 
perature, in unusual moisture or drought, or in a combination 
of two or more of these factors. Diseases often attack insects, 
and genuine epidemics occur, sweeping off millions in one stage 
or the other. The natural enemies are legion ; many vertebrates 
are largely dependent for their food upon insects, and this is 
especially true of birds and reptiles, some of which subsist upon 
insects exclusively. A large proportion of the insects themselves 



46 



AN ECONOMIC ENTOMOLOGY. 



Fig 



are predaceous, and live upon others of their kind ; great num- 
bers are parasites, their prey being other insects of all orders, 
and in this way forms that depend upon plant life for their sub- 
sistence are kept within definite bounds. These bounds, though 
they may vary from year to year, never change much except 
where man interferes. This subject will be touched upon in an- 
other place more fully. 

Except in rare instances insects are of two sexes, male and 
female, and we nowhere find among them true hermaphrodites. 
In the plant-lice and gall-wasps we have apparent exceptions ; 
but these are only apparent. 

In the female the most prominent sexual organs are the ovaries. 
These consist of two sets of tubes, one in each side of the abdo- 
men, usually below the digestive system, united 
at their base into one larger tube called the 
oviduct ; the two oviducts unite, just before 
opening outwardly, into a single chamber 
called the vagina. The vagina opens out- 
wardly at the end of the body, sometimes with- 
out special modification, sometimes by means 
of a flexible or extensile tube, sometimes as a 
long, rigid cylinder, and occasionally in the 
form of a sting. These structures, be they 
rigid or otherwise, are always called ovipositors, 
and their function is to place the egg into the 
position necessary for its best development. 
Associated with this system are a number of 
glands, the use of which is either to give a 
sticky coating to the egg, enabling it to adhere 
to the leaf or other point at which it is laid, or 
to supply a poisonous secretion, where such is 
necessary for defence or for stupefying prey. 
There is also a little sac, attached by a slender 
duct to the vagina, at about the point where 
the two oviducts unite. This is the seminal 
receptacle, and in this is received the seminal 
from it the eggs are fertilized as they pass from 
the oviduct into the vagina on their way through the ovipositor. 
In some insects these receptacles are very large, especially where 




Ovarian tubes of one 
side, in Polistes, show- 
ing eggs in all stages 
of development, with 
nutritive cells, n m, be- 
tween ; r s, seminal re- 
ceptacle ; ov, oviduct ; 
vag, vagina. 



fluid of the male 



STRUCTURE AND CLASSIFICATION. 



copulation takes place in the fall, and the female, living through 
the winter, does not begin to lay eggs until some time in spring. 
The eggs have at one end small openings termed micropyles, and 
through these the spermatozoa find their way into the egg to 
fertilize it. In the ovarian tubes a variable number of cells are 
developed, and these grow rapidly, each cell eventually forming 
an egg. The number of tubes and the number of cells in the 
tubes vary within wide limits in the different species. In some 
they are rigidly limited, and the insects are able to lay only a 
definite number of eggs ; in others the cells are so numerous that 
a definite number seems unlikely. Before the female has been 
impregnated the ovarian tubes are very slender and occupy only a 
little space in the abdomen. When the eggs develop, however, 
the ovaries increase in size until, finally, the abdomen is almost 
entirely occupied by them, and is often enormously distended. 

In the male the ovaries are replaced by the testes, which also 
are more or less coiled tubular structures, and these tubes, like 
the ovaries, unite to- 
gether on each side into ^5- 
a larger tube, which in 
turn are combined into 
a single organ, usually 
more or less horny in 
structure, — the penis. 

Reproduction among 
insects is, therefore, in 
its essentials, like that 
of the higher animals. 
The only difference is 
that as the life period is 
shorter, the eggs must 
all be laid within a defi- 
nite time, and they are 
very much greater in 
number. It further 
proves that we have a 
definite development in 

insects as in higher animals, and that with them also, like pro- 
duces like, — that is to say, the product of the egg when fully de- 




Male organs of May-beetle. — One side only beyond 
the ductus ejaculatorius, duct, ejac; glni., mucus 
glands; ves. sem., s&ra.\xva\ vesicles; vas. def., vasa 
deferentia. 



48 



AN ECONOMIC ENTOMOLOGY. 



veloped will be like the parent that laid it, and never anything 
else. Insects are as a rule unable to reproduce until they have 
reached the adult stage, and the few apparent exceptions may 
not be real when all the factors are understood. An insect, when 
once adult, never changes into one of a different kind ; so a 
beetle can never change into a cricket, nor a small fly into a 
larger one. 



CHAPTER VIII. 

GROWTH AND METAMORPHOSIS. 

Insects grow only in the larval stage, and motdt, or change 
their skin, every time there is an increase in size. As has been 
stated, the insect crust is rigid and inelastic, and extension is 
possible only by the expansion of the membrane between the 
rings. When a growing insect reaches the extent of the elasticity 
in its covering, a new skin forms beneath the old one, and the 
latter splits, allowing the newly-clad and much larger specimen 
to crawl out of it. In this respect insects resemble crabs, lobsters, 
and other crustaceans. 

The terms larva, pupa, and adult have been several times used 
in the previous chapters, and need more explanation. Most 
insects undergo, in the course of their life, a series of changes or 
transformations, in which their form, appearance, and habits are 
often so diverse that the different stages could not be recognized 
as belonging to one species without definite, continued observa- 
tion. These changes are termed metamorphoses, and they 
include the egg, larval, pupal, and adult stages. With few 
apparent exceptions, all insects begin in an egg stage, and the 
method in which this egg is developed has been already described. 
In this stage, whether it be long or short, the creature is unde- 
veloped and quiescent, except for the changes going on within, 
and which do not result in outward movement. In rare cases 
the eggs are not extruded from the body of the insect, but fertili- 
zation takes place in the ovary, the larvae hatching within the 
abdomen of the mother. 

From this egg comes in due time a larva, a minute creature 



STRUCTURE AND CLASSIFICATION. 



49 



which may or may not resemble the parent that laid it. Assum- 
ing that it does, it is without trace of wings. It grows apace, 
moults as often as necessary, and at last attains very distinct wing 
pads. It is now in the pupal stage, and with the next moult the 
wings become fully developed. It is then adult and fitted to 
reproduce its kind. This sort of metamorphosis is said to be 
incomplete, because there is no inactive stage, and because there 
is always a close resemblance in all stages. The larvae are quite 
usually termed nymphs, and differ from the adults only in size, in 
the absence of wings, and in the undeveloped sexual characters. 
A peculiarity of this method of growth or moulting is worthy of 
incidental mention. When the insect moults, it is not the outer 



Fig. 26. 




Moulting of a grasshopper. — a, nymph ready to change ; b, the skin split along the 
back and the adult emerging ; c, continues the process, and at d, the adult insect 
drying out. 

skin alone that is affected : all the most delicate mouth parts with 
their hairs and processes are cast and replaced by a new cover- 
ing ; the lining of a large proportion of the digestive system 
is shed, and the inner coat or surface of the tracheal tubes is 
renewed, so that practically the insect gets, in part, a new diges- 
tive system and a new breathing apparatus, every time it increases 
in size. The number of these moults varies in the different orders, 
and even in species of the same order. There may be as few as 
three or four, and there may be twenty or more. We can some- 
times modify the normal number by changing the circumstances 
under which the insects live. Thus, the larva of the common 
Dermestid found in museum cases normally moults four times 

4 



AN ECONOMIC ENTOMOLOGY. 



before it is ready to change to a pupa. I have confined several 
larvae in vials, closed them tightly with rubber stoppers, and sup- 
plied a small amount of food. In these dry vials larv^ae have 
lived for months, in one case more than a year, and apparently 
as a mere pastime they moulted at intervals, so that in one vial 
there were eight or ten cast skins, more than doubHng the ordi- 
nary number of changes. Withal the insects did not increase in 
size, simply because no more food was supplied. 

Where the metamorphosis is complete, there hatches from 
the egg a grub, caterpillar, slug, maggot, or other crawling or 
wormlike creature, quite unlike the parent. Growth continues, 
as before, by moulting, until the full size has been attained, and 
then feeding ceases. The larva now seeks some retired spot, 
sometimes spinning a silken covering termed a cocoon^ and then 
changes to a chrysalis or pupa. The term chrysalis is used in 
the butterflies, where it is free and often prettily ornamented, and 
the term pupa in most other cases. In this stage it is inactive 
and rests quietly for some time. The character of the future in- 
sect is usually more or less clearly defined, but occasionally it 
resembles neither the larva that formed it nor the adult insect 
which is to come from it. In due time the adult emerges as a 
butterfly, moth, beetle, fly, or bee, and no trace remains of the 
previous larval condition. Insects never grow after they reach 
the adult stage, but remain of exactly the same size as when 
first they emerged from the pupa. Thus, as has been indicated 
in the previous chapter, large flies are never the parents of small 
flies, nor do small flies ever grow to become larger flies. 

This cycle of change in an insect is termed its life history, which 
it is sometimes very difficult to work out. Scarcely two species 
are alike in habit during all their lives, and a complete knowledge 
of the full life cycle and the habits in all stages is essential to an 
intelligent appHcation of remedial or preventive measures. 

It is often possible to reach an insect easily in one stage, or at 
one period, where it is naturally protected during all others. So 
we may, sometimes, by a little change in farm practice, or by 
taking advantage of some preference on the part of the insect, 
avoid injury. To ascertain all these facts and to suggest the 
treatment indicated, is the work of the economic entomologist. 
Watching the transformations of an insect is a delightful task, 



STRUCTURE AND CLASSIFICATION. 



51 



and one that can be easily accomplished in most cases by any 
one possessing a little patience. In leaf-feeding insects all that 
is necessary is to bring in a supply of food with the larva upon 
it, and keep it in a box or cage, renewing from time to time, so 
that fresh food may be always available. In the bottom of the 



Fig. 27. 




A breeding-cage of the Riley pattern. 



box there should be three or four inches of clean sand for the 
benefit of those forms that go underground to change to a pupa, 
and in due time the caterpillar or slug will, under the observer's 
very eyes, change to a butterfly, beetle, or other insect, accord- 
ing to the character of the larva. 



PART II. 
THE INSECT WORLD. 



CHAPTER!. 

GENERAL CLASSIFICATION. 

Those structures which are of economic importance and, in- 
cidentally, those that are used in classification have been described 
in the first part. 

Classification is the arrangement of the insects into series 
which are so related to each other that a species never before 
seen may be recognized, and its place ascertained from certain, 
easily discernible, structural characters. 

Insects that agree in structure usually have similar habits, and 
by placing an example into its systematic position, the probable 
life cycle becomes also known, and its exact life cycle can be 
more easily and intelligently traced out. 

The divisions used are orders, families, genera, and species. 
The term sub- may be prefixed to either, to indicate a division 
not marked enough to claim full rank. 

A species is the ultimate division, and consists of individuals 
which agree with each other in appearance, structure, and life 
history, mating freely and producing progeny, which resemble 
the parents. An assemblage of such species agreeing in general 
characters forms a genus, and this is a more or less uncertain 
division, depending somewhat upon the opinion of the systematic 
student. A series of genera agreeing in form, structure, and 
life history makes a family, and famihes are united into orders. 

For the division into orders, use is made of wings and mouth 
structures and of the transformations. 

For convenience in ready classification the Linnsean orders are 
here adopted, though some of them have been properly sub- 
52 



THE INSECT WORLD. 



53 



divided. The new orders are referred to, however, in the proper 
place. 

Lowest of all are the Thysaiiura, including "bristle-tails," 
* * spring-tails, " " fish-moths, ' ' and the like. They never become 
winged or develop even a trace of wings. The mouth parts are 
small, retracted, usually formed for biting, but sometimes so 
undeveloped as to be almost without type. The metamorphosis 
is incomplete ; indeed there is only a simple increase in size, and 
nothing really worthy of the term development. In most cases 
the abdomen bears a pair or more appendages at the tip, from 
which some of the common names are derived. 

Next come the Neuroptera, or nerve-winged insects. These 
have four well-developed wings, membranous, more or less 
transparent, and so crossed by numerous veins that they seem 
reticulated or netted : from which character they derive their 
name, which means nerve-winged. The mouth parts are man- 
dibulate, usually well developed, but sometimes almost obsolete. 
In its broadest sense the order includes "May-flies," "dragon- 
flies," " caddice-flies," "white ants," "stone-flies," "lace-wing 
flies," and the like. There are, however, two types of meta- 
morphosis, — one complete, the Neuroptera proper, and the other 
incomplete, the Pseudo-neuroptera. It is here that most of the 
new ordinal divisions have been made. 

A step in advance are the Orthoptera, or straight-winged 
insects, such as roaches, crickets, katydids, and grasshoppers. 
They have two pairs of well-developed wings, — the first or ante- 
rior usually narrow and a little thickened or parchment-like; the 
second or posterior broader, plaited or folded like a fan beneath 
the anterior pair. The mouth parts are formed for biting, and the 
metamorphosis is incomplete. 

The order Hemiptera, or "half-winged" insects, includes all 
the true ' ' bugs ;' ' and to members of this series only the term 
"bug" is properly appHed, according to entomological opinion. 
The order is always distinguishable by the mouth structure, which 
is haustellate, and consists of a jointed beak, concealing two pairs 
of slender, pointed lancets. The metamorphosis is incomplete. 
The term Hemiptera, or ' ' half-winged, ' ' is derived from the fact 
that in the typical series the primaries are thickened at base and 
thin or membranous at tip. In it we have such creatures as the 



54 



AN ECONOMIC ENTOMOLOGY. 



' ' chinch-bug, " " squash-bug, ' ' and others of equal note. The 
term Homoptera^ or similar- winged," is used for that series in 
which the fore-wings are uniform in texture, as in the plant-lice 
and Cicadas. 

The order Coleoptera contains the beetles, and the name, mean- 
ing sheath- winged," is due to the fact that the anterior wings 
are hard and horny, unfitted for flight, and used only as a sheath 
or covering for the posterior pair. The mouth parts are man- 
dibulate, and the metamorphosis is complete. 

An easily recognized order is the Lepidoptera, or "scaly- 
winged," including the butterflies and moths. Here wings and 
body are covered with minute scales, easily rubbed ofl" and 
resembling colored dust. The mouth parts are haustellate, and 
form a coiled tongue, which is usually concealed beneath the 
head, but can be readily extended at the will of the insect. The 
metamorphosis is complete. 

Equally recognizable are the Diptera, or "two-winged" flies. 
The single pair of wings is characteristic, and with it are asso- 
ciated mouth parts varying much in type, but never mandibulate 
nor forming either a coiled tongue or jointed beak. The meta- 
morphosis is complete. 

The Hymenoptera, or "transparent winged" insects, include 
bees, wasps, ants, and the like, and stand at the head of the 
Class Insecta. They have two pairs of transparent wings, with 
only a few veins ; the posterior smaller than the anterior. The 
mouth parts are mandibulate, but the tongue is often developed 
as a lapping organ, and sometimes greatly enlongated. The 
metamorphosis is complete. 

To show the differences succinctly the following table may be 
of use : 

Insects which never become winged, have the mouth feebly developed 

and the metamorphosis incomplete . Thysanura, 

All others are winged : 
With four transparent wings, which are net-veined and flat ; mouth 
parts mandibulate and well developed ; the metamorphosis, either 

incomplete Pseudo-neuroptera. 

or complete Neuroptera. 

With the fore-wings narrow and somewhat thickened ; the posterior 
folded fan-like, or plaited ; mouth mandibulate ; transformations 
incomplete Orthoptera. 



THE INSECT WORLD. 



55 



With fore-wings thickened at base, thin at the tip ; mouth parts form- 
ing a jointed beak ; transformations incomplete .... Hemiptera. 

With the fore-wings uniform in texture ; mouth parts and transforma- 
tions as before Homoptera. 

The fore-wings are horny, and useless for flight, serving only as a cov- 
ering for the posterior pair ; mouth mandibulate ; metamorphosis 
complete Coleoptera. 

All the wings and the body covered with scales ; mouth parts developed 
into a long coiled tongue ; transformations complete Lepidoptera. 

The wings transparent, with only a few longitudinal veins; mouth 
mandibulate, the tongue formed for lapping ; transformations com- 
plete Hymenoptera. 

Two wings only ; mouth parts haustellate ; transformations complete 

Diptera. 



CHAPTER II. 

THE THYSANURA. 

Spring-tails, Bristle-tails, Fish-moths, etc. 

Under this term are grouped a number of lowly insects which 
never become winged, and can hardly be said to have any real 
transformations. Most of them are small, soft bodied, with 
feebly developed mouth parts, and live in damp earth, among 
decaying vegetable matter. Some live under bark of dead or 
decaying trees, or in decaying wood, while in rare instances spe- 
cies are found preferring dry and warm localities. Among those 
that live in damp places are forms without eyes, and with no de- 
veloped tracheal system, the necessary oxygen being absorbed 
through the skin itself. Compound eyes are developed in a few 
instances only, though ocelli are usually present. 

Peculiar to the order are certain abdominal appendages. In 
some cases these are in the form of rudimentary abdominal legs, 
indicating a relationship to the Myriapods or Centipedes ; but 
more often they consist of bristles or filaments attached to the 
anal segment. In the simplest form they consist of long, many- 
jointed appendages, whose function may be tactile, similar to 
that of the antennae. 

A good example of this type is the little creature known to 



56 



AN ECONOMIC ENTOMOLOGY. 



Fig. 28. 



house-keepers as the "fish-moth," or "silver fish." It is one 
of the few species that prefers a dry, warm locality, and is found 

in cupboards and closets, hiding in 
crevices, and running rapidly when 
disturbed. It is about one-quarter 
of an inch in length, oblong, a little 
pointed towards both ends, and has 
the body covered with minute, sil- 
very-white, gHstening scales. It is 
one of the largest species belonging 
to the order, feeding upon starchy 
substances and food remnants. It 
sometimes becomes troublesome in 
libraries, gnawing the calendered 
surface of leaves and bindings and 
defacing them. The insect can 
scarcely be said to be injurious, but 
it is often annoying, and may be 
driven out by a free use of pyre- 
thrum dusted in corners and crev- 
ices. 

A much more common type is the 
"spring-tail," so named from the 
fact that the anal appendages consist 
of two short, bristle-like processes, 
arranged to enable the insect to leap 
or spring. They are normally bent 
under the body, held in place by a 
catch-like organ until the insect de- 
sires to move suddenly, when the 
catch or spring is released, sending 
the insect forward a surprisingly long 
distance. When excited it progresses by a series of rapid leaps 
of this kind, its course being decidedly erratic because no two of 
the springs are made in the same direction. 

"Spring-tails," or Podurids, are found in moist locaHties, 
wherever decaying vegetable matter occurs. In manure beds 
they often occur in millions, and on warm days may come to the 
surface in astounding numbers. I have seen a forcing bed cov- 




Bristle-tail or fish-moth ; Lepisma sp. 



THE INSECT WORLD. 



57 



ered nearly half an inch in depth by a solid mass of these little 
creatures not one-sixteenth of an inch in length. Frequently a 

Fig. 29. 




Papyrus species : showing spring curved under the body. 



Fig. 30. 



sudden rise of water on meadow or bog land drives them out of 
their hiding-places, and they leap about on its surface for a time 
as readily as they do on land. I have seen, on cranberry bogs 
reflowed late in May, square rods of the surface so densely cov- 
ered that nothing of the water was visible. 

They are often found in damp cellars, on any vegetable matter 
stored there, and are sometimes ac- 
cused of promoting decay. In the 
fields a cut potato placed underground 
may attract dozens of specimens that 
feed upon the juices of the raw sur- 
face, and they have been therefore ac- 
cused of producing scabby potatoes. 
They are of all colors, but usually 
slate-gray or yellowish, the markings 
sometimes quite pretty and distinct. 

As a matter of fact, these insects 
are never injurious. Healthy vege- 
table tissue is not attacked by them, 
and their mouth parts are adapted for 
feeding on soft or moist tissues only : 
hence a decayed or bleeding spot at- 
tracts them. They are sure to occur in manure and on manured 
land, and can be kept out to a large extent by using only mineral 




A Podurid, or spring-tail, found on 
manure beds. 



58 



AA^ ECONOMIC ENTOMOLOGY. 



or " commercial" fertilizers. In the manure itself they are bene- 
ficial rather than otherwise, hastening its decay by changing the 
form of the more resisting portions. 

It sometimes happens that, when found associated with decay 
or rot of stored produce, the insects are accused of causing it ; 
but they always follow and never precede or cause the diseased 
appearance. 



CHAPTER III. 

THE NEUROPTERA AND PSEUDO-NEUROPTERA. 

May-flies^ Dyago7i-flies^ Stone-flies ^ Caddice-flies , etc. 

The old term Neiiroptera comprised all insects with four more 
or less transparent wings, reticulated or netted with numerous 
longitudinal and transverse veins, and the mouth parts formed 
for biting. As thus defined the order was easy of recognition, 
and, practically, the division is convenient here, for nowhere in 
this series are any species injurious to field crops. We find 
troublesome species among the parasites, and the Termites, or 
"white ants," are injurious under some circumstances ; but, as a 
broad statement, subject to a few exceptions, it is correct to say 
that no Neuroptera are injurious to field crops, and no appre- 
hension need be felt whatever the numbers in which they may 
appear. 

It was early found that under this term insects quite different 
in life habits were included, some having complete and some in- 
complete metamorphoses. The order was then divided, the term 
Pseudo-neuroptera being applied to those forms in which the 
transformations are incomplete. The division is a good one ; 
but, as there is nothing in the adult to indicate to the tyro the 
nature of the changes it undergoes, it was not alw^ays easy to de- 
cide to which order a given insect belonged. More recently the 
series has been yet further divided, and we have now somewhat 
compact groups of net-veined insects which may be recognized 
without much trouble. These will be referred to in order under 
their modern names. 



THE INSECT WORLD. 



59 



Fig. 31. 



Order EPHEMEROPTERA. 

This order includes what are known as ' ' May-' ' or ' * day- 
flies," the names indicating either the 
time at which they first appear or 
the brief period of their adult life. 
"May-flies" occur most abundantly 
during spring or early summer, in the 
vicinity of lakes, ponds, and rivers. 
They are readily recognized by their 
fragile body, terminated by two or 
three long, thread-like appendages, and 
by their large, frail wings, the posterior 
much smaller than the anterior. They 
fly at night, and are readily attracted 
to light, dozens being often seen hov- 
ering around a single street lamp. I 
have seen bushels of them at the base 
of electric lights on the banks of the 
Ohio, and the shores of the Great 
Lakes are sometimes covered with 
heaps six inches or more in depth, so 
that the stench from the decaying 
bodies becomes nearly insupportable. 
The head is large, the eyes are round 
and prominent, and the forelegs are 
conspicuously long and stout ; but the 
feelers are reduced to mere rudiments, and the mouth parts are 
atrophied and utterly useless for feeding purposes. 

In the May-flies we have the survival of an ancient type, their 
generalized structure indicating a low place in the scale of devel- 
opment. The eggs are laid on the surface of the water and sink 
gradually to the bottom. From them hatch narrow, elongate- 
oval, more or less flattened larvae, furnished laterally and some- 
times at the end of the body with gill-tufts, living in the mud 
ooze of river and lake bottoms, under stones, or among aquatic 
plants. They feed on all sorts of minute animal life, and prob- 
ably also upon the low forms of vegetation on submerged stones 
or sticks. They grow slowly, moult frequently, and live from 




May-fly and its larva. 



6o 



A.V ECOXOMIC EXTOMOLOGY. 



one to three years in this condition. Wing-pads gradually 
appear, and eventually the adults emerge and fly away, only to 
shed their skins once more in theyery act of flight. I haye seen 
their delicate, pure-^vhite exuyiae float about oyer the Ohio Riyer 
in such numbers as to resemble a fall of snow. This moulting of 
the adult is peculiar to the Ephemerids, who mate soon after it 
occurs, deposit their eggs, and before morning perish, — their 
life-work accomplished. 

Not all forms are so short-liyed, however, some requiring sev- 
eral days to complete oviposition ; but their inability to feed 
indicates a brief existence at best. The number of species is large, 
and the number of specimens immense, indicating an active, 
aquatic insect life at least as great as that found in the air or on 
the dry land. While the larvae feed on smaller creatures, they 
are in turn devoured by fishes, who find in them an important 
article of food, and in this view only are they of any economic 
importance. 

Order ODONATA. 

Under this head come the dragon-flies, or. as they are often 
termed, "devil's darning-needles," "spindles," or "snake- 
doctors." Many superstitious beliefs are connected with these 
insects, and there is a general indisposition to handle them, be- 
cause of their supposed ability to sting. The insects are common 
about ponds and streams, flying rapidly over the surface of the 
water, occasionally darting down to touch its surface, and delight- 
ing always in the bright sunshine. 

The body is long and slender, fitted with an enormous head 
principally occupied by the eyes, and with two pairs of long nar- 
row wings, which are similar in size and appearance. In some 
species there are leaf-like appendages at the end of the abdomen, 
and these are erroneously supposed to be weapons of ofience. 
The legs are stout, clothed with spines and spurs, as well as with 
long claws at the tip. The mouth is formed for biting, the man- 
dibles and maxillae being greatly developed and sharp-toothed, 
for tearing their prey. 

They are, as has been indicated, predaceous. and capture their 
food during flight, their powerful wings and legs enabling them to 
overtake and grasp any creature that comes within the range of 
their huge eyes. Flies and mosquitoes are the usual victims, and 



THE INSECT WORLD. 



6i 



hence the term ' ' mosquito hawk' ' has also been appUed to 
them. 

It has been suggested that dragon-flies might be artificially- 
propagated to lessen the mosquito pest ; but this is not feasible, 
because they fly only during the day, while the mosquito is 
decidedly more a creature of the night. No dragon-fly volun- 
tarily remains in woods, except along streams and in open glades, 
yet here mosquitoes lurk by the million. The proposition looks 
well at first sight, but is not practical. 



Fig. 32. 




Dragon-fly and its development. — Larva and pupa feeding at i and 3; 2, nymph ready 
to change ; 4, a pupa skin from which 5, the adult, has emerged. 



The early stages are passed under water, and the larvae are 
ugly creatures, somewhat resembling the adults, but without 
wings. They move sluggishly among the aquatic vegetation, or 
on the mud of the bottom, strongly resembling the latter in 
color. They do not swim readily, but some are able to propel 
themselves by drawing into the posterior part of the digestive 
tract a quantity of water and then expelling it forcibly. This 
process really answers a double purpose, for this same tract is 
suppUed with numerous fine tracheal tubes through which oxygen 
is drawn from the water : two functions, respiration and locomo- 
tion, being thus curiously combined. Respiration is also carried 
on by means of leaf-like anal appendages, in which trachea ramify 
in all directions, forming gill-like structures. As the larvae grow, 
wing-pads appear, and when these are fully developed the pupal 
stage has been reached ; the insects continuing active, however, 



62 



AX EC 0X0 MIC EXTOMOLOGY. 



until ready for the change to the adult. Then they crawl up the 
stem of some water plant, or upon a projecting stone, and soon 
the skin splits and the imagos emerge. A few minutes suftice to 
harden and dry the newly-developed adults, then with spread 
wings they sail away on a new career, in a new medium. 

In habit the larvae are as predaceous and voracious as the adults, 
and their prey consists of any aquatic forms which they can cap- 
ture, — mosquito larvae forming quite a staple article of diet. It 
has been already indicated that they are not very active creatures, 
and prey is captured by simply waiting in the mud or on a mossy 
stone until it comes within reach. Their color renders them 
almost invisible under such conditions, and nature has furnished 
a remarkably extensile mouth structure, by means of which they 
are able to reach out some distance and seize whatever creature 
may be passing near. It is the labium, or lower lip, that is 
modified for this purpose, and is supplied with a double hinge 
which can be straightened out rapidly to bring into play a pair of 
large, slender, and pointed jaws at its tip. When this structure is 
retracted it is invisible, covering the other mouth parts entirely and 
hiding them. The term ' ' mask' ' has therefore been applied to it. 

Oviposition varies with the species, and is interesting. The 
sexes pair during flight. The male has the organs of copula- 
tion at the base of the ab- 
domen, while the opening 
of the testes is at the tip. 
Before pairing he fills the 
seminal pouch at the base 
of the abdomen, then grasps 
the female by the neck with 
a pair of anal claspers, and 
she curves up the tip of 
her abdomen into contact 
with the opening to the 
seminal duct of the m.ale. 
As the eggs are fertilized 
the pair descend to the 
surface of the water, the 
female drops a little mass upon the surface, and copulation is 
resumed, the process being repeated until all the eggs are laid. 





A species of Agrion and its larva ; the latter with 
anal g;ill-tufts. 



THE INSECT WORLD. 



63 



In some species the female when impregnated crawls under 
water, down the stem of some aquatic plant, and lays her eggs 
on stones, plants, or even in the mud. By folding the wings 
backward, close to the body, a film of air is gathered which keeps 
the insect dry and supplies it with a sufficient amount of oxygen 
for a temporary return to its old medium. 

The order contains no injurious species, because all are pre- 
daceous ; but, on the other hand, none are markedly beneficial, 
because, though they devour an enormous number of other 
insects, these are not usually species destructive to farm crops. 



Order PLECOPTERA. 

The ordinal term signifies " plaited wing," and is used because 
the hind wings are longitudinally folded or plaited beneath the 




Stone-fly, Perla bicaudata, and its larva. 



anterior pair, which rest flat upon the back. The insects them- 
selves are called "stone-flies," and are loosely jointed, flattened. 



64 



A A' ECONOMIC ENTOMOLOGY. 



the thoracic parts large and not closely united, the wings exceed- 
ing the abdomen in length. In texture they are rather soft, and 
the antennae are long and many-jointed. They frequent the 
margins of streams and running ditches, preferring damp, shady 
localities. The mouth parts are mandibulate, but their food 
habits are not well known. They are not injurious, and are 
economically important only as food for fishes. The eggs are 
laid in masses upon the surface of the water, through which they 
sink to the bottom. The larvae are flattened, live among and 
under stones, feeding upon vegetation, and probably also upon 
such small, soft-bodied creatures as come in their way. The legs 
are well developed and of nearly equal size. The antennae are 
long and slender. There are usually slender, hairy appendages 
at the end of the abdomen, and on the under side are tufts of gill- 
like structures serving for respiration. In some species these 
gills persist even in the adult, forming a remarkable exception to 
the general rule that adult respiration is through spiracles only. 
One natural family the Perlidcs^ comprises the entire order. 

Order PLATYPTERA. 

The ordinal term signifies " flat winged," or " broad winged," 
and in those forms in which wings are present the secondaries 
are not folded or plaited, but lie flat over the body, covered by 
the primaries. The mouth parts are mandibulate, the thoracic 
rings are loosely jointed, and as a rule the insects have a flattened 
appearance. In most cases the head is large and prominent, 
wider than the thoracic rings. 

Three distinct families, using that term loosely, are grouped in 
this order, differing greatly from each other, all of some economic 
importance, and requiring more detailed consideration. 

Family termitid^. 
Termites, or ' ' white ants, ' ' as they are called, from their 
appearance and habits, occur all over the United States, but are 
more common southward. They are separated as a distinct 
order under the term Isoptera, meaning similar-winged, and are 
interesting from their social organization, which is complicated, 
several forms or castes existing in each colony. All our species 
live in and feed upon woody or fibrous material, though extend- 



THE IXSECT WORLD. 



65 



Fig 



ing their galleries through the soil, often for great distances, and 
also inhabiting underground chambers. 

In woodland almost any log or decaying tree will be found 
swarming with these dirty yellowish-white insects, about one- 
fourth of an inch long, readily recognizable by their large heads 
and oval, obtusely- 
terminated abdomen. 
They are wingless, and 
when exposed to light 
seek at once to make 
their way back into 
darkness. These are 
workers, and blind ; 
they never voluntarily 
come out of their gal- 
leries, all their wander- 
ing being in tunnels of 
enormous length run 
over or under ground 
in every direction from 
the main nest. If they 
must reach a point 
to which they cannot 
burrow, they build a covered way 
woody and excrementitious matter= 




Tertties flavipes. — a, larva ; b, winged male ; c, worker ; 
d, soldier ; e, female ;/, pupa. 



of earth mixed with saliva, 
These workers are the most 
familiar to the casual obser\^er, and form much the greater pro- 
portion of the inhabitants of a nest or colony. They have distinct, 
hard, brown mandibles, not excessive in size, and can be thus 
readily distinguished from the soldiers, which are larger, with 
proportionately larger heads and very largely de\'eloped mandi- 
bles. The soldiers form a standing army whose duty it is to 
protect the community ; therefore, if we disturb a colony the 
workers at once run away, leaving the field to the soldiers, who 
are impotent enough in the daylight, blindly gnashing their jaws ; 
but are no doubt useful in the ordinary routine of Termite life. 
Early in spring we find, in addition, larger, winged individuals, 
chestnut-brown in color, and these are the true sexed forms, 
male and female. On a bright, warm day, when spring is well 
advanced, these individuals, which by the bye are furnished 

5 



66 



A AT ECONOMIC ENTOMOLOGY. 



with eyes, leave the parent-nest in great numbers and fly about, 
enjoying for a few brief hours the sun and air. They are then 
said to be "swarming," and select their mates, returning to the 
surface before the setting of the sun. Out of the vast numbers 
leaving the nest few survive the day of flight. They have numer- 
ous enemies, and, even if they escape these, must depend upon 
being found and adopted by some vagrant workers before they 
are able to form a colony. The sexed individuals — king and 
queen — are helpless, can do nothing for themselves, and are not 
permitted to return to their old home. This serves to keep the 
insects in check, for the chances of starting a new colony are 
very small. Let us assume, however, that a pair is adopted and 
housed, the workers at once building a proper habitation for the 
royal pair. Reproduction begins immediately, and the female, 
now stripped of wings by her own act, gradually enlarges, the 
abdomen ultimately becoming a mere egg-sac. Such a queen 
becomes the mother of the colony, and she is tolerably prolific : 
sixty eggs a minute have been counted, making a possible output 
of over eighty thousand in a single day ! The workers take entire 
charge of the eggs and resulting young, feeding and tending 
them until they are able to take part in the ordinary work of the 
colony. Both males and females are represented among the 
larval forms, but it seems to depend entirely upon the nurses as 
to what caste is to result. They are able at will to arrest devel- 
opment and to produce whatever forms are needed in the com- 
munity. Thus workers and soldiers are each of both sexes, but 
the sexual organs never become developed or functional. A 
certain proportion are allowed to develop fully, and these furnish 
the annual swarms. If the queen becomes old or unable to sup- 
ply the colony with a sufficient number of young, the workers 
provide for a number of " complemental" males and females. 
These never become winged, reaching only the pupal stage in 
which the wing-pads appear, and they never leave the nest, but 
pair within it, the female laying fertile eggs, though never in such 
numbers as a perfect queen. Therefore, several of these comple- 
mental pairs may inhabit a colony, and there may be no real 
queen at all. Curiously enough, no queen of our common species 
has ever been found, and we are yet in ignorance of just where 
the royal chamber is situated. 



THE INSECT WORLD. 



67 



Termites become injurious in one of two ways : they either eat 
into wood-work of furniture and buildings, or they attack grow- 
ing plants. In the Northern and Eastern United States they 
confine themselves to dead wood, and we have only a single spe- 
cies, — Termes fiavipes ; but in the South and Southwest they 
attack living plants, among them orange-trees and sugar-cane. 
In buildings they sometimes live in beams, weakening them to 
such an extent as to threaten or actually cause collapse. Not 
many years ago some of the heavy wooden supports of the Bos- 
ton State House were found infested, and more recently a build- 
ing in Cleveland, Ohio, was invaded, requiring prompt measures 
to prevent accident. They also attack stored products in gen- 
eral, skilfully concealing their presence by leaving the outer sur- 
face untouched. Thus, in a pile of old records stored in a vault of 
the United States Department of Agriculture, a large proportion 
was found badly injured, though no external trace appeared. In 
the United States National Museum is a mass of black linen 
thread from a South American store-house in which the outer 
form of a pile of skeins is accurately preserved, while all below 
is a mass of hard, black galleries. These are made of the partly 
digested and excreted thread itself ; and so we find that in the 
galleries in logs or trees the walls are composed of partly digested 
wood-fibre. 

Termites are often found in decaying stumps, and sometimes 
in the roots and stems of weak and dying plants ; in the latter 
case often hastening or inducing death. In the Southern States 
they are more abundant and troublesome, attacking sugar-cane 
and also eating the bark of orange-trees at the crown. 

REMEDIAL MEASURES. 

Where the insects are found in buildings, injecting bisulphide 
of carbon into their galleries will destroy them. They should be 
traced to their outside nest, if possible, and, when found, this 
should be destroyed. Frequently an old stump of some large 
tree may be a centre from which a district becomes infested, and 
the bisulphide should be liberally employed wherever the insects 
are obser^^ed in numbers. 

On growing plants the bisulphide is also useful in many in- 
stances ; but here, too, the effort should be made to discover the 



68 



AN ECONOMIC ENTOMOLOGY. 



central colony, rather than to protect individual trees or plants. 
Hot water has been recommended, but is not so effective as 
the bisulphide. Dead stumps and partly dead, infested plants 
should be removed and burnt, to deprive the insects of congenial 
quarters. 

The true home of the Termites is in the tropics, where they 
are pests of the first magnitude. In Africa some of the species 
are mound-builders, erecting turreted structures from ten to fif- 
teen feet in height, made up of earth and partly digested wood 
and other fibre. 

Family psocid^. 

To this family belong the minute "book-lice" often found in 
dusty corners, under loose paper, in collections, and in other dry 
localities. They are always small, resembling somewhat a 
' ' Termite' ' in miniature, very active, running backward or for- 
ward with equal facility, and furnished with very long, slender 



bedding being especially favored, to the horror of the housewife, 
who almost invariably mistakes their true character. Several 
times within my experience I have received these creatures with 
anxious entreaties for a remedy, and equally anxious requests for 
secrecy. The Psocids may be always distinguished from para- 




FiG. 36. 



antennae or feelers. The head 
is very large, with small, 
coarsely granulated com- 
pound eyes. The mouth or- 
gans are mandibulate, but 
not at all prominent, and 
fitted for gnawing rather than 
biting, — whence the insects 
have been called Corrodentia 



A book-louse, X 25 diameters. 



or "gnawers." They are 
white or dirty-yellow in color, 
and look just enough Hke 
true lice to be mistaken for 
them under some circum- 
stances. Occasionally con- 
ditions favor their increase in 
houses, and almost in a day 
it will be overrun, beds and 



• 



THE INSECT WORLD. 



69 



sites by their very rapid motions and their long antennae or 
feelers. Their food is starch, where they can get it, or dry ani- 
mal or vegetable matters, and they can be driven out by a free 
use of naphthaline crystals. Their injury in libraries is done by 
eating the starched surface of bindings, plates, and pages, and 
so disfiguring them. 

The forms just described are all wingless throughout their en- 
tire life, Atropos ( Clothilld) diviriatoria and A. pulsatoria being 
common species. In some mysterious way the term "death- 
watch' ' has been applied to these creatures, and they have been 
credited with making the ticking sound often heard at night in 
old houses, and which is supposed to give warning of a death to 
come. 

But there are some winged forms, and these somewhat resem- 



FiG. 37. 




Psocus Uneatus, much enlarged. 

ble overgrown plant-lice, differing, of course, by the mandibulate 
mouth. These winged Psocids sometimes occur in great num- 
bers on the bark of trees, in my experience most often on cherry 
and orange, where they feed upon lichens and other dry vege- 
table matter. They sometimes create alarm when great numbers 
are noticed by the farmer ; but none of them are in the least in- 
jurious. They are more cylindrical in appearance than the wing- 
less forms, and the thoracic parts are better developed and larger 
than the head, which bears the same coarsely granulated eyes 
and long antennae. When a group of specimens is disturbed 
they run in every direction, and often drop to the ground 
rather than use their wings in flight. Altogether, this family 



70 AN ECONOMIC ENTOMOLOGY. 

contains insects that simulate injurious forms, while doing little 
or no actual damage themselves. 

Family mallophagid^. 

The literal meaning of this term is ' ' wool eater, ' ' and it ap- 
propriately expresses the habits of some of the species. All 
members of this family are parasitic, and are known as biting 
lice ; never sucking blood, but feeding upon young hair, feathers, 
skin-scales, clots of blood, and scabby or other scurfy material 
found on the skin or among hair and feathers. They infest 
warm-blooded animals only, and principally birds, whence the 
term ' ' bird-lice' ' has been erroneously applied to the entire 
group. All the common farm animals except the pig are infested 



Fig. 38. 




Biting-lice.— a, dog-louse, Trichodectus latus ; b, sheep-louse, Tm'ckodectus sphcero- 
cephalus ; turkey-louse, Go?iiodes stylifer. 



by some species of this family, and all the poultry or fowls are 
troubled to a greater or less extent. 

The insects are all small, flattened, with large, prominent head, 
often bulging eyes, and short antennae or feelers. The legs are 
short and stout, fitted for holding to and moving among hair or 
feathers, and the abdomen is oval. No trace of wings is ever 
developed. 

The eggs are fastened to the hair or feathers of the host, and 
in a few days the young emerge, not differing from their parents 
except in size and sexual immaturity. The entire life is thus 



THE INSECT WORLD. 



71 



passed on the host, and the insects usually spread from one 
animal to the other on occasions of contact, or through litter 
into which some specimens may crawl or be thrown. They also 
crawl upon the wood-work of coops and stables, and thence upon 
such animals as may rest against it. 

The only way to reach these insects is by means of poisons 
acting through the respiratory system, and this is not difficult, 
because the spiracles are not well protected. Barn-yard fowls 
will keep themselves tolerably free if furnished with plenty of fine 
dust. The finer it is the more effective, and the birds will so 
thoroughly powder themselves that few of the parasites can 
escape. Cleanliness on the roosts and in hen-houses is impera- 
tive, and a liberal use of whitewash and occasionally of kerosene 
on all the wood-work is useful. A badly infected house may be 
cleaned by shutting it up tight for twenty-four hours, and evap- 
orating in a shallow dish a few ounces of bisulphide of carbon. 
This kills all, save eggs, and the treatment should, therefore, be 
renewed a week later to reach such as may have hatched since 
that previously made. It has also been recommended to hang 
small open vials of bisulphide below the perches, and this, it is 
asserted, kills the parasites without discommoding the fowls. 

On farm animals greasy mixtures may be successfully employed, 
or carbolic or tobacco washes or dips. For larger animals — 
horses, cows, or mules — a thorough grooming with comb and 
brush, dipping the brush into a kerosene emulsion diluted five 
times so as to moisten all parts of the body, is decidedly the best 
method. This must be duplicated a week later to reach any that 
may have hatched from eggs since the previous treatment. On 
large herds, badly infested, the kerosene emulsion, diluted nine 
times, is simply sprayed on the animals as they pass through a 
narrow opening, the application renewed at intervals of a week, 
until no more lice appear. 

With so considerable a range of remedial and preventive 
measures no serious trouble from these parasites need be appre- 
hended, and it remains only to urge again the utmost cleanliness 
everywhere as the best of all preventive measures. 

All the neuropterous orders heretofore treated have had the 
metamorphosis incomplete, and are therefore classed as pseudo- 



72 



AA^ ECONOMIC ENTOMOLOGY. 



or false-neuroptera. While they are not directly followed in the 
classification by the true neuropterous series, yet for convenience 
they may be so arranged here, and not entirely without reason, 
because they are descendants of the same stock. 

Order NEUROPTERA. 

As this term is now limited it includes only those ner\x- 
or net-winged forms with complete metamorphosis in which 
the biting mouth parts are well developed and not prolonged. 
The thoracic parts are large, frequently the prothorax is dis- 
tinctly separated and square, and the entire insect is somewhat 
flattened. 

Of this type are the large forms like Corydalus 2,ndChaiiliodes, 
and the peculiar Raphidia found on the western coast, members 
of the family SialidcB. The head is large and broad, the mandi- 
bles well or, as in the male Coiydalus, even enormously developed, 
the antennae long and many jointed ; in Chauliodes pectinated. 
The prothorax is always distinct, square or oblong, in Raphidia 
very long and narrow, the other thoracic segments w^ell developed 
and loosely held together. The abdomen is soft in texture, and 
as a whole the forms appear loosely jointed. The broad wings 
he nearly flat on the back and much exceed the tip of the ab- 
domen, the hind pair being partially folded at rest. The eggs 
of Corydalus are laid in masses on leaves or sticks, coated with a 
water-proof secretion, and from them hatch flattened six-footed 
larvae, which live under stones or other shelter on the bottom of 
running streams. They are furnished with gill tufts, through 
which they obtain oxygen, and prey on whatever insects or lar\^ae 
may come within their reach. In turn they are preyed upon by 
fishes, and the lar\^ae of the Corydalus corjiutus, or ''dobson," 
make excellent bait, being locally known as " hellgrammites. " 
When full-grown they come to the edge of the stream and, under 
stones or other shelter, change to quiescent pupae, in which aU 
of the limbs are free and the form of the future adult is fully 
shown. 

The species of this family are interesting, but of no sort of 
economic importance. 

Not so the next family, the Hemerobiidcs contains numer- 
ous species of interest, all of them predaceous and beneficial to 



THE INSECT WORLD. 



73 



Fig. 39. 




The " hellgrammite" or " dobson" in all its stages. — Upper series : a, the larva; b, the 
pupa ; c, the male adult ; d, the head of the female : in the lower series the leaf bears 
egg masses at aa, enlarged at be; d, the larva just hatched, with details from e to j. 



74 



AN ECONOMIC ENTOMOLOGY. 



the farmer. There are several sub-families, which together are 
termed "lace-winged flies," from their delicate, finely-reticulated 
or netted wings, which lie flat and are not folded. The insects 
are slight, and in the species allied to Hemerobius the colors are 
brownish or smoky. They are less common than the forms 
allied to CJuysopa^ which are green, with long antennae and 
prominent, bright, yellowish-brown eyes, which have given them 
the name * ' golden-eyed flies' ' in some localities. They are 
commonly found in fields or along the edges of woods, and emit, 
when handled, a peculiarly sickening odor which is quite unmis- 
takable when once known. In the adult stage the insects feed 
little or not at all ; but the larvae, known as "aphis-lions," feed 
almost constantly, their prey being small, soft-bodied insects of 
all kinds, aphids or plant-lice ranking as special favorites. 



Fig. 40. 




A lace-winged fly, Chrysopa oculata. — a, the eggs ; b, the larva ; d, same, feeding on a 
pear-psylla ; e, cocoon, from which /, the adult, has escaped ; g, head of adult in front, 
enlarged. 

The entire life history of the insects is interesting. The female 
in ovipositing touches the end of the abdomen to the surface, — 
usually a leaf, — upon which the eggs are to be laid, and then 
elevates her body about a quarter of an inch, emitting at the 
same time a viscid thread which hardens on exposure to the air. 
At the tip of this the egg is fastened, and we get thus a little 



THE INSECT WORLD. 



75 



gro\'e ot eggs on stilts. This is supposed to insure their safety 
from wandering predaceous forms that might otherwise feed upon 
them. When the larva hatches it climbs down the slender 
thread, and attacks and feeds upon the first suitable specimen it 
can find, — usually a young plant-louse. Now, here is another 
peculiarity : it does not chew or tear its prey, but holds it firmly, 
sucking the juices by means of grooves on the inner side of the 
large mandibles, which are closed by the slender maxillae. The 
larva grows rapidly, becoming rather more than a quarter of an 
inch in length, narrow, spindle-shaped, pointed at the anal ex- 
tremity, the head distinct and with prominent sickle-shaped 
mandibles. When full-grown it spins, by means of anal glands, 
a perfectly spherical, white, silken cocoon of very dense texture, 
and small in proportion to the larva. It resembles a moderate 
sized pearl in form and appearance, and when the adult is ready 
to emerge, a circular lid is lifted off to give the matured pupa 
exit. Comparing the fully developed insect with the cocoon 
from which it issued, the marvel is great that it was ever packed 
away in so small a space. 

These insects are really of much practical value, frequenting, 
as many of them do, tilled fields and orchards, feeding upon 
larvae, plant-lice, and similar creatures. They become injurious, 
however, in some parts of California, where they attack and 
destroy coccinellid or lady-bird larvae. 

Somewhat closely allied in all stages to the Hemerobiidce are 
the MyrmeleonidcB , or "ant-lions," but they are larger, with 
longer and narrower wings, and clubbed antennae. As before, 
the adults are graceful, harmless creatures, which fly mostly at 
night, while the larvae are predatory, resembling the ' ' aphis- 
lions" in structure, save that they are broader and chunkier in 
appearance. They are also peculiar in that many of them 
capture their prey in pits or traps. 

In constructing its trap, the larv^a usually selects a spot of mod- 
erately compact, fine sand, and excavates a funnel-shaped pit 
with the sides as steep as the sand will lie. It remains buried 
and invisible in a little gallery at one side of the bottom, in wait 
for any unlucky creature that may come within reach. Ants are 
the most frequent victims, from their wandering habits and their 
tendency to investigate, a pause at the brink resulting in a slip of 



76 



AN ECONOMIC ENTOMOLOGY. 



sand and a tumble into the jaws of the enemy. Should the ant 
recover a footing before reaching the bottom, a shower of sand, 
^.^^ ^ sent by the vigilant 

larva below, over- 
whelms and brings 
it down to its death. 
When the juices 
are exhausted, the 
empty shell is 
thrown out and the 
pit is repaired for 
other victims. 
Sometimes pits are 
made in saw-dust 
or friable leaf mold 
and some make no 
pits at all. 

The adults are 
of two rather dis- 
tinct series : the 
first with short 
antennae which 
thicken rather gradually toward the tip, including Myrmeleo ; the 
second with long, slender antennae, enlarging suddenly into a 
flattened club. The head is larger and the body more robust, 
covered with stiff bristly hair, giving the insects a fierce appear- 
ance. The most common genus is Ascalaphus, and the larval 
habits are not known, though it is probable, from what w^e learn 
of foreign species, that they do not build pits or traps. Though 
interesting, the family is of no economic importance. 

An odd family is the MaiitispidcB , so named from the peculiar 
resemblance which they bear to the Orthopterous genus Mantis. 
The species are not common, and are easily recognized by the 
enormously developed forelegs, which are fitted for grasping, and 
are inserted into a long and slender prothorax. They are pre- 
daceous, while their larvae are parasitic in the egg-sacs of spiders. 
The eggs are laid on stalks, as with the "lace-wings," and the 
slender larvae that hatch from them live through the winter with- 
out food, becoming active again in spring, when they seek the 




Myrmeleo species. — The adult above ; the larva in its pit, 
which is shown in section. 



THE INSECT WORLD. 



77 



egg-sacs of Lycosid or running spiders. The larva, that succeeds, 
enters the sac and begins feeding upon the eggs, gradually losing 
its active form and becoming clumsy and grub-like. The pupa 
forms within the larval skin, and after midsummer the adult 
appears. 

Very curious creatures are the PanorpidcE, or ' ' scorpion- 
flies," usually ranked as an order under the term Mecoptera. 
They have netted wings similar to but more robust than the 
" lace-wings," but have the mouth prolonged into a beak, at the 
end of which the biting parts are situated. In the genus Pan- 
orpa the males have a pair of huge anal forceps, curved up some- 




legs and body from the side. A Panorpa, or scorpion-fly, and its larva. 



what like the sting of a scorpion, and from this the common name 
is derived. As a matter of fact, the insects are entirely harmless 
save to others of their kind, for they are predaceous. The genus 
Bittacus is narrower winged, with unusually long legs, looking 
somewhat like a crane-fly at first sight. Species belonging to the 
genus Boreus occur on the snow in very early spring. The larvse, 
so far as we know them, are predaceous and resemble caterpillars 
in appearance ; they have eight pairs of fleshy prolegs, however, 
while no true caterpillar ever has more than five. None of the 
species are common and none are of practical importance to the 
farmer. 

The " caddice-flies" have also been elevated to ordinal rank 
under the name Trichoptera., or ' ' hairy-winged. ' ' The adults 
have moderately developed bodies, with large wings, which are 
more or less densely clothed with hair, the first pair often thicker 



78 



AN ECONOMIC ENTOMOLOGY. 



than the second, which are folded beneath them. Both wings 
have numerous longitudinal veins connected by only a few cross- 
veins, losing the reticulated appearance of the more typical Neu- 
roptera, and resembling more closely some of the lower moths, 
for which, indeed, some of the smaller forms may be easily mis- 
taken. The mouth parts, however, though rudimentary, are 
mandibulate in type, and there is no approach to the coiled 
tongue of the Lepidoptera. The antennae are very long and 
slender, resembling hairs rather than jointed organs. 

The species are found frequently in great numbers along the 
banks of streams, ponds, or ditches, in which the larval life is 
passed. The larvae are caterpillar-like, with three pairs of unusu- 
ally well-developed legs, and live in cases which they make of 
bits of sticks, moss, leaves, stones, shells, or other material, held 
together by silken threads with which the entire inside of the 
habitation is lined. Frequently the cases are roughly and irreg- 
ularly constructed ; but as often they are marvels of skilled work- 
manship. Small 



mon name ' ' caddice ' ' or case-flies. Whatever the form of the 
case, the insect lives in and carries it about everywhere through- 
out the larval life, crawling about under water by means of the 
large legs and keeping the soft, white, hind body constantly pro- 
tected. Some live in ponds or sluggish streams, others in rapid 
brooks and torrents ; some are vegetarians, some are predatory, 
feeding on other larvae or even on small fish. Some forms con- 



FiG. 44. 



stones are fitted so 
carefully that no 
break as large as 
a needle-point oc- 
curs, and some- 
times they mimic 
shells so closely 
that conchologists 
have been deceived 
into believing them 
such. In these 
cases the lai*vae live, 
and from them they 
obtain their com- 




A caddice-fly, Limnophilus vhombicus, its larva, and at a 
the larval case. 



THE INSECT WORLD. 



79 



struct effective nets in which very young fish become entangled 
and fall easy victims to the insect fishermen. Streams in which 
these kinds of caddice-flies are abundant are not easily stocked 
with fish unless the fi-y is so well grown as to be out of danger 
fi-om this source. Practically, the insects are of no importance 
to the agriculturist. 



CHAPTER IV. 

THE ORTHOPTERA. 

Grasshoppers, Crickets, Katydids, etc. 

The order Orthoptera, or "straight-winged" insects, includes 
those forms with biting mouth parts and an incomplete meta- 
morphosis, commonly known as "earwigs," "grasshoppers," 
"locusts," "crickets," and "roaches." 

The distinctive characters, aside from those just mentioned, 
are that the fore-wings are firmer in texture than the secondaries, 
and that the latter are folded fan-like, or plaited, when at rest. 
They are then covered by the primaries, which are usually nar- 
row and of little use in flight, resembling in this respect the wing- 
covers of the beetles, and here termed "tegmina." With few 
unimportant exceptions the insects belonging to this order are 
herbivorous, and among them are some of the most destructive 
pests to agriculture, such as the migratory locusts or grasshop- 
pers, which have been known and dreaded since the dawn of 
history, and the "Rocky Mountain locust," of evil repute in 
our own country. 

First come the ForficulidcB , or ear-wigs, generally accepted 
as forming a separate order under the name Dermaptera (skin- 
wing) or Euplexoptera (well-folded wing). They differ from all 
the other Orthoptera by having a pair of anal forceps and by 
their resemblance to the Staphylinidce, a family of half-winged 
beetles. The wing-covers are short and thick, not extending to 
the middle of the flattened abdomen, and the large hind wings 
are first plaited fan-like around a point near the middle of the 
anterior margin, and are then transversely folded into a neat little 



8o 



AN ECONOMIC ENTOMOLOGY. 



packet, which is tucked away under the fore-wings by means of 
the anal forceps. Some of the species, however, lack the wings 
entirely, in which case the peculiar anal forceps and the beetle- 
like form distinguish them quite readily. 



Fig. 45. 




Cases or caddices, made by the larvae of Trichoptera, illustrating differences of shape 
as well as varieties of material used. 



Except in the South, ear-wigs are rare in the United States, 
and not injurious. In parts of Europe and in sub-tropical and 
tropical countries they are sometimes abundant and frequently 
annoying, eating at night into flowers in which they hide during 
the day. In vine- and flower-covered houses or arbors they are 
sometimes a nuisance, and their long, slender form and nocturnal 
habits have given rise to the unfounded belief that they crawl 
into the ears of sleepers and kill them. The female lays a small 
number of eggs only, and broods over or watches them until 
some little time after they are hatched. 

The more typical Orthoptera may be conveniently divided 
into series by their leg structure and method of locomotion, as 
follows : 



THE INSECT WORLD. 



8l 



1. The Ctcrsoria, or "runners," with stout, long legs fitted 
for rapid motion, — like the roaches. 

2. The Raptoria, or "graspers," in which the forelegs are 
developed into grasping organs and the insects are predaceous, 
— in strong contrast to all the others of the order. 

3. The Ambulatoria, or "walkers," in which the legs are 
long and slender, useful for deliberate progress only. 

4. The Saltatoria, or "jumpers," which have the hind legs 
unusually long and well developed, fitted for leaping, — like grass- 
hoppers and crickets. 

Fig. 46. 




Ear-wig.— I, mature male ; 2, nymph ; 3, the wing, showing the radiate type of pleating. 

The Cursoria, or "runners," belong to the family BlattidcB, 
or roaches. They are flattened, rather soft, repulsive creatures, 
with long, powerful, spiny legs ; long, slender, filiform antennae, 
and the head bent under the body so as to locate the mouth 
parts between the front legs. They are brown or yellow in color, 
are nocturnal in habit, and live under bark or in crevices, for 
which their flattened form suits them peculiarly well. 

Roaches eat almost anything, or are practically omnivorous. 
They are among the most ancient type of insects, and are yet 
disgustingly common in the tropics, their numbers decreasing 
northwardly until only a few cosmopolitan forms are found do- 
mesticated in houses. 

A peculiar feature in the life history is the method of oviposi- 
tion. The eggs mature at about the same time, and are closely 
packed into a somewhat bean-shaped case, which the female car- 
ries about with her, partially protruding from the end of the ab- 
domen, for several days. It is then deposited intact in some 

6 



82 



AN ECONOMIC ENTOMOLOGY, 



Fig. 47. 



convenient crevice, and very soon thereafter the young issue. 
Modifications of this habit occur, and in some cases the eggs act- 
ually hatch within the body of the mother, 
who thus becomes viviparous. 

I am not aware that roaches ever become 
injurious to growing crops in our country ; 
but two species are certainly great nuisances 
in houses, — the *'Croton bug," Phyllo- 
dromia germanica, and the " black beetle," 
Periplaneta orientalis. Both are introduced 
and almost cosmopolitan forms. The former 
is small, averaging about half an inch in 
length, and is winged in both sexes. The 
latter is larger, varying between three- 
fourths and one and one-fourth inches, with 
short wings in the male and mere rudiments 
in the female. 

The most satisfactory way of dealing with these insects is by 
means of a phosphorus paste, spread upon bits of soft bread 
and placed near their haunts, all other food particles being care- 
fully put out of reach. A short period of such treatment will 
usually prove effective. Almost as good is a mixture of equal 




Forficula tczniata, male 
and female. 



Fig. 48. 




The Croton bug, Phyllodromia germanica.—a, first stage ; b, second stage ; c, third 
stage ; d, fourth stage ; e, adult ; /i adult female with egg-case ; g, egg-case, enlarged ; 
h, adult with wings spread. All natural size except^. 



parts of finely powdered chocolate and borax, dusted into the 
crevices where the insects hide. The mixture should be inti- 
mate, and is best made in a mortar, so that with each part of 



THE INSECT WORLD. 



83 



chocolate, of which the roaches are very fond, they will get also 
a particle of borax, which is poisonous to them. This mixture 
has proved successful in many instances within my own experi- 
ence, and has the advantage of being cheap as well as non-poi- 
sonous to man. 

The Raptoria, or "graspers," form one family, the Majitidce^ 
as odd in appearance as their habits are unusual. They are 
clumsy, heavy-bodied insects, with short, broad wings, the 
middle and hind-legs rather weak, but with an unusually long 
and slender prothorax, to which is attached a pair of huge 
forelegs, armed with sharp spurs and spines. The head is usu- 
ally much broader than the prothorax, with prominent, often 
globular eyes, short antennae, and so set as to be capable of lat- 
eral motion. It is, in fact, the only type capable of turning its 



The insects are, as a rule, sluggish, those occurring with us 
incapable of rapid motion, depending entirely upon such prey as 



The Oriental roach, Periplaneta orientalis. — a, the male ; b, the female ; c, egg-case. 



comes within easy reach, and securing this through their often 
remarkable resemblance to the vegetation among which they 
lurk. In other countries there are some more active species, 
capable of pursuing and capturing their prey. Their colors are 
green or yellowish, like leaves, or brownish, like bark ; the wing- 
covers sometimes mottled and roughened to mimic an irregu- 
larity or overgrown injury on a trunk or branch. Thus con- 



head ! 



Fig. 49. 




84 



AN ECONOAlIC ENTOMOLOGY. 



cealed, they rest, body close to the surface, prothorax elevated, 
and forelegs held in the attitude of prayer, whence the term 
"praying mantes," Ma?itis religiosa, which is applied to a for- 



FiG, 50. 




Stagmojuantis Carolina. — c, the female ; h, the male. 



eign species. But prayer is far from the object in view, as any 
small insect that happens within reach learns to its cost. A sud- 
den clasp wounds and crushes it into helplessness, and the Mantis 
then leisurely devours its victim, the forelegs serving admirably 
as hands in the operation. 

The eggs are laid in a mass on twigs or branches, held to- 
gether by a peculiar silken fibre which encases and protects each 
egg as well as the entire cluster. 

The predaceous habit excludes these insects from the categor}^ 
of injurious forms ; but they are not sufficiently common in our 
country to be of any practical advantage. They are southern in 
geographical range, and only one species, Stagmomajitis ca7'o- 
lina, is rarely found north of New Jersey on the Atlantic coast. 

The Ambulatoria, or "walkers," include a series of very 
curious species, popularly known as "walking-sticks" and 
"walking-leaves," represented in our fauna by a few species 
belonging to the family Phasmidce. The true home of these 



THE INSECT WORLD. 



85 



Fig. 



forms is in the tropics, where we find excellent examples of pro- 
tective mimicry in the development of w4ngs so colored and 
veined that the insects cannot be easily distinguished from the 
foliage upon which they feed. Our own species have mere rudi- 
ments of wings only ; but have very long, slender bodies, an- 
tennae, and legs. When at rest, with long legs fully stretched 
out, the resemblance to a bare twig or a torn leaf is perfect. 

The insects move slowly and awkwardly, feeding on the foliage 
of a variety of forest trees, and are occasionally quite destructive. 
They do not extend north of the Middle States 
on the Atlantic Coast, but occur everywhere in 
the Central and Southern States, reaching 
northwardly in the Mississippi Valley much 
further than in the East. So far as I am aware, 
they never attack field or orchard crops, and 
are not strictly injurious to agriculture, though 
they may be to forestry. Unlike the families 
previously mentioned, they take no care of their 
eggs, but the females drop them at random upon 
the ground. It has been said that in a badly- 
infested piece of woodland the pattering of the 
eggs as they fall from the trees sounds like rain. 

Thoroughly and carefully burning over in- 
fested woodland during some favorable period 
in winter will prove effective in case remedial 
measures become necessary ; spraying with 
arsenites can be resorted to for the protection 
of single or small groups of trees. 

In the Saltatoria^ or ''jumpers," we find the 
most destructive species, and they separate 
readily into three families : the AcridiidcB, or 
' ' short-horned grasshoppers ;' ' the Locustidce, 
or "long-horned grasshoppers" and "katy- 
dids ;" and the GryllidcB, or " crickets," which 
have long horns or antennae like the Locustidcs, 
but cylindrical instead of flat, sword-like ovipositors. 

The Acridiidce, or short-horned grasshoppers, are among the 
most common and best known of our insects, flying up or jump- 
ing out of the way, however one turns, among grass or low herb- 



Egg masses of 
Stagmomantis Car- 
olina, from above 
and from side. 



AN ECONOMIC ENTOMOLOGY. 



Fig. 52. 




Walking-sticks, Diapheromerafemorata.—a and b, the eggs, enlarged, from the edge 
and side; c, young just hatching ; d, the male, and e the female adult. 



THE INSECT WORLD. 



87 



age in roads, fields, or meadows, but not favoring dark woods. 
They have no external ovipositor, but the female is furnished 
with four horny valves, between which the eggs pass, and which 
are also useful in making the hole, in soil or wood, into which the 
eggs are laid. The term ' ' short-horned, ' ' as applied to these 
insects, is relative, and means that the antennae are moderately 
stout, the joints well marked, and the whole member not as long 
as the entire insect, — in fact, rarely even half as long. A curious 



Fig. 53. 




Rocky Mountain locust ovipositing. — a, a, females with abdomen inserted in the soil ; 
b, an egg-pod broken open and lying on the surface ; c, a few scattered eggs ; rf, section 
of soil removed to show eggs being put in place ; e, an egg-pod completed ; f, an egg- 
pod sealed over. 

character is a pair of ears situated one on each side of the basal 
segment of the abdomen, and we therefore expect and do find 
that most of the species are capable of making some kind of 
song or noise, though this ability is confined to the male. 

A series of species characterized by a very receding front, 
meeting the vertex of the head in an acute angle, is referred to 
the sub-family Tryxalincs, of which there are many species 
throughout our country, none of them abundant enough to be 
injurious. They are partial to low, sedgy land or meadows, es- 
pecially on sandy soil, and I have met with the species most 
abundantly near the sea, or on the sandy plains not far inland. 
Some species are common on or near cranberry bogs, but are not 
injurious. 

Quite a series of species is referred to the sub-family CEdipodincB , 



88 



AN ECONOMIC ENTOMOLOGY. 



and these differ from the preceding in that the front meets the 
top of the head in an even, obtuse curve. The species are 
usually long-winged, and the thorax is either crested or rough 
and tuberculate, with somewhat prominent and sharp angles. 
Quite usually the hind wings are brilliandy red or yellow and 
black, sometimes blue, and frequently contrasting in color. To 
this sub-family belong those species that fly early in spring and 



green-striped locust (yCIiortophaga viridifascid), which occurs 
over a large part of the United States, and has the hind wings 
without strong contrasts ; and the large, red-winged Hippisciis 
discoideus, which is more southern in its range, not extending 
north of New Jersey. Species of this kind are most frequent in 
barren, sandy, or partly desert regions, and few ever become 
injurious. 

Among the troublesome forms are the Carolina locust," Dis- 
sosteria Carolina, and the long-winged locust, Dissosteria longi- 
pennis ; the first found throughout the United States, and easily 
recognized by its large size and the ample, black, yellow-bordered 
hind wings ; the latter a similar but somewhat longer-winged 
western species, usually confined to the Rocky Mountain region, 
but sometimes migrating for considerable distances from their 
normal breeding-places. These species deposit their eggs in the 
ground in the fall and the young hatch in the spring. 

The ' ' Carolina locust' ' is often met with in late fall, clinging 
fast to the tops of plants, killed by a fungous disease which 
ordinarily keeps the species within bounds. It is further con- 
spicuous by its habit of poising a few feet from the surface, and 
making a continuous " whirring" or rasping sound. 

The sub-family Acridiince is one of great extent, containing 
those grasshoppers that have become famous by their evil deeds, 




Chortophaga viridifascia- — a, larva ; b, adult. 



Fig. 55. 



have wintered in 
an immature stage, 
ready for the trans- 
formation to the 
adult form as soon 
as the weather per- 
mits. Good ex- 
amples of such 
species are the 



Fig. 58. 




Fig. 54, Syrbula admirabilis . Fig. 56, Hippiscus discoideus. Fig. 57, Dissosteira 
Carolina. Fig. 58, Schistocerca americana. Fig. 59, Melanoplus spretus. Fig. 60, Mela- 
noplus atlanis. 



THE INSECT WORLD. 



89 



and it differs from the preceding in having the breast between the 
anterior legs produced into an obvious tubercle or pointed pro- 
cess. The prothorax is usually smooth and quite even, rarely 
ridged or crested or even angulated, and the hind wings are not 
often contrastingly colored. 

The typical genus Acriditcm of older authors contained the 
long-winged forms, which, hatching in great numbers in their 
natural haunts, sometimes find food insufficient, and are seized 
with a migratory mania that impels them to rise, by what seems 
common consent, and fly to fresh fields and pastures new. Such 
swarms may number uncounted millions of specimens, and they 
leave a wake of devastation which only those who have seen can 
appreciate. 

The species described in biblical history is the Schistocerca 
peregriiium, or true migratory locust, and is strongly resembled, 
except in size, by the Schistocerca americana of the Eastern 
United States, which is common and sometimes destructive in the 
South, but becomes more rare northwardly, until in Central New 
Jersey it is but occasionally seen. In all the species oi Acridmm 
the wings are longer than the abdomen, and in the males the tip 
of the abdomen is not swollen. The sexes in these insects are 
easily distinguished, because the female abdomen terminates in 
four pointed, horny valves, or pieces, no trace of which is found 
in the males. 

Perhaps this is a convenient place to describe the life history 
of grasshoppers, or AcridiidcB^ in general. The eggs are most 
frequently laid in the ground, though sometimes in partly de- 
cayed wood, the horny valves already mentioned serving to 
make the holes. The species that oviposit in the ground select 
a moderately hard or compact soil where obtainable, not too 
densely covered with vegetation, and then force the abdomen 
into it as deeply as possible. When this is accomplished the 
eggs are laid, each coated with a gummy secretion which causes 
it to adhere to its neighbor and to form a pod, extending almost 
to the surface. The hole is then closed, and becomes indis- 
tinguishable except on close examination. In this state they 
remain through the winter, the young hatching during the fol- 
lowing spring or early summer. The term nymph rather than 
larva is employed for these young, unfledged grasshoppers, and 



90 



A AT ECONOMIC ENTOMOLOGY. 



in this stage their travelling powers are limited, though their 
appetite is not. Yet even now they are able to cover consider- 
able distances if a short food supply makes it necessary. The 
wing-pads, which become visible early in the nymphal life, increase 
in size until the insect is ready for its final change, and when this 
occurs its powers for destruction are multiplied by the new facility 
in travelling. In some species the wings never become devel- 
oped even in the adult ; but these are easily distinguished from 
the immature stages of winged forms, because in the latter the 
rudiments of the hind wings always cover those of the fore- 
wings, while in adults, even when the wings are mere stumps, 
the secondaries are always overlaid or covered by the others. 

Our best-known migrating forms belong to the genus Melan- 
oplus, in which the anal extremity of the males is enlarged and 
swollen. Here we find the Melanoplus spretus, or ' ' Rocky 
Mountain locust, ' ' which in years past has caused ruin in many 
States west of the Mississippi, and even yet does much injury 
and periodically threatens disaster. The home of this species, 
about which volumes have been written, is on the high, dry, 
eastern slopes of the Rocky Mountains, and in some regions 
west of these mountains in Idaho and Utah. There it breeds 
abundantly each year, frequently extending into the adjacent 
regions to obtain food and maintaining itself for some time. As 
a result of any unusual increase in numbers with a corresponding 
failure of food-supply, emigration may become necessary, and the 
long, broad wings of the species suffice to carry it even to the 
Mississippi River, ranging north and south from Minnesota to 
Texas. But in these moist eastern regions the insect cannot 
thrive, and from millions of eggs laid only a small proportion of 
weakly larvae appear, which usually die before they mature. 

An allied but shorter-winged form is the Melanoplus atlanis, 
or "lesser locust," which occurs commonly over all the more 
northern United States, while the M. femur-rubrum, or ' ' red- 
legged locust," is much the most common eastern species, some- 
times doing considerable injury to crops. 

Among the more common short-winged forms we have in the 
East species of Paroxya, in which the males are smaller and 
ready fliers, the females much larger, with wings covering half 
the abdomen, and used rather as aids in leaping than as organs 



THE INSECT WORLD. 91 

of actual flight. The species of Pezotettix and alHed genera are 
short-winged in both sexes, are of medium or small size, and 
prefer cool or shady spots on mountain sides, among rocks, at 
the edges of woods, or in similar localities, hence never become 
economically important. The species are most numerous in the 
West and South. 



Fig. 61. 




a b 
Lubber grasshoppers. — a, Dictyophorus reticulatis ; b, Brachystola jnagna. 



Two very large and clumsy species occur, both known as 
"lubbers;" one in Florida, short-winged, yellow and black, is 
Dictyophorus reticulatis, — the other, a Western plains species, 
dirty-brown in color, and with mere rudiments of wings, also 
known as the " Buffalo grasshopper," is Brachystola magna. 

Last to be mentioned in this series are the "grouse locusts," 
or TettigincB. These remarkable little creatures have the pro- 



92 



AN ECONOMIC ENTOMOLOGY. 




Tettix. 



thorax very much developed and extended backward so as to 
cover a large part or even all of the abdomen. They frequent 
banks of streams and moist places, resembling in color 
Fig. 62. dead leaves or muddy flats where they often occur, 

and they are powerful leapers. Many of the species 
are found as adults early in spring, while I have found 
others in September. None of them are known to be 
injurious. 

REMEDIES. 

The question of remedies against the "locust," or 
short-horned grasshopper, is an important one, not 
always easy of solution. As the country is brought 
into more complete cultivation the ' ' grasshopper' ' pest will natu- 
rally decrease, injury from the migrating forms only remaining to 
be dreaded. 

In the general life history it was said that a large proportion 
of the eggs are laid in fall, remaining unhatched during the 
winter. The young nymph, or larva, is a feeble insect, able to 
dig to the surface through the way opened by the pod, or through 
loose soil, but scarcely otherwise. Fall-plowing the infested land 
is therefore a most effective remedy. If the pods are deeply cov- 
ered, the young die attempting to get to the surface ; if lightly 
covered or exposed, their natural enemies find them easily ; and 
when the pods are broken, rain and sunshine induce decay or 
disease, and the eggs never hatch. Where grasshoppers other 
than the migratory forms are troublesome, systematic fall-plowing 
will effect a prompt reduction in their numbers. Special or lim- 
ited localities, like cranberry bogs, are sometimes infested, and in 
such cases turkeys are effective. They prefer grasshoppers to 
almost any other food, and, if allowed to run where such abound, 
will eat nothing else. In some cases the arsenites may be used 
to protect crops which are easily sprayed, and occasionally 
' ' driving' ' will answer for the fledged insects. 

Larval forms in grass or short vegetation can be collected in 
large pans or "hopper-dozers," drawn by men or horses, and 
coated with coal-tar, crude petroleum, or other sticky substance, 
and of all these the crude petroleum is to be preferred. 

As against the migratory forms in their permanent breeding 
grounds, I have no suggestion to make here. The subject has 



THE INSECT WORLD. 



93 



been treated at great length in the reports of the U. S. Entomo- 
logical Commission and of the U. S. Department of Agriculture, 
and these must be consulted : the methods discussed and recom- 
mended are too numerous for reference here. In the invaded 
regions fall plowing to destroy the eggs and the use of the 
"hopper-dozers" on the young are indicated. 

Under some circumstances, when the number of grasshoppers 
is not too great, they may be destroyed, or a large measure of 
protection may be secured, by tempting them with poisoned 
bran, of which they seem to be rather fond. It should be com- 
posed of bran and Paris green, at the rate of one part of Paris 
green to fifty by weight of bran, thoroughly moistened with 
sugar water. Cabbage patches can often be protected in this 
way against grasshoppers that come from uncultivated land, and 
there are other cases where such a measure is of value. Indi- 
vidual judgment must determine those cases. 

The LocustidcB are "long-horned grasshoppers," "meadow 
grasshoppers," and "katydids," distinguished at once by very 
long, slender antennae, rarely shorter than, and usually much 
exceeding, the body. They are green in color as a rule, with 
slender legs and thin wings, and we find them a vast array of mu- 
sicians, — always the males only, — the sound-producing structure 
occupying a triangular area at the base of the fore- wings, where 
they overlap. Here one or more of the 
veins is elevated and ridged on each wing, 
and bv rubbino- these ridgfed surfaces to- 
gether a strident sound is produced, in- 
tensified by a membrane tightly stretched 
between them. The pitch and volume of 
the * ' song' ' are regulated by the develop- 
ment of veins and membrane as well as of 
the tegmina, no two species being alike in 
this respect. Special students of the family ^T^^^fl^ P°^'tion of 

. •' the base of the wmg m Cono- 

soon learn to recognize the sounds made c^?/Aa/z^5, showing the ridged 
by the different species as certainly as or- ^'^^"^ sound-producing 
nithologists know birds by their song. The 

ears through which the songs appeal to the courted females and 
competing males are situated on the fore tibiae, and are essentially 
like the same organs found on the abdomen of the AcridiidcB. 




94 



AN ECONOMIC ENTOMOLOGY. 



Another feature peculiar to this family is the exserted, promi- 
nent, blade-like ovipositor of the female, which indicates an es- 
sentially different method of oviposition. This, in fact, exists, 
for the eggs are mostly laid in plant tissue, — usually in the stems 
of reeds and grasses, among which some forms abound, — some- 
times in woody tissue ; rarely in leaves, the edges being split to 
receive them ; and only occasionally are they laid externally. 
Certain cricket-like species are exceptions, and oviposit in the 
ground. 

The most prominent, from their large size, are the species 
loosely termed "katydids," — insects which are familiar by their 
song, but are not always personal acquaintances, because they 
are most active and noisy in the evening, and prefer trees and 
shrubs to more modest plants. The true ' ' katydid' ' is Cyr- 
tophyllum concavum, much the heaviest in build of all our spe- 
cies, with very broad concave wing-covers and an unusually 
developed sound-producing structure. In fact, the entire fore- 
wings are immense sounding-boards, enabling the insect to make 
itself heard at great distances. It produces its characteristic note 
three or four times in succession, with slight intervals only, bear- 
ing thus a semblance to " Ka-ty-did" or " Ka-ty-did-n't :" oc- 
casionally it merely rasps out ' ' Ka-ty. ' ' 

This species lays its ovate, slightly convex eggs into the twigs 
or trunks of trees late in fall, and the young appear during the 
early summer following. 

One of the most common of the large species, found over a 
great part of the Northern United States, is the Micjvce7itrum 
retiJiervis, replaced in the South by the allied M. lau7'ifoliu77i, 
which lay their large eggs externally in regular rows on the edges 
of leaves, on twigs, or on any sort of likely or unlikely place, — 
e.g. , the pulley-strap of a sewing-machine. The Southern spe- 
cies is the more common, and in Florida becomes injurious to 
young orange-trees by eating the foliage. They can be kept in 
check on such trees by collecting and destroying the eggs during 
winter, by collecting the insects themselves, or by spraying the 
foliage with one of the arsenites. 

The genus Scudderia contains smaller, narrower-winged spe- 
cies, in which the tegmina are not expanded in the middle and 
the ovipositor is curved sharply upward. They frequent shrubs 



Fig. 68. 




Fig. 64. 





g6 AN ECONOMIC ENTOMOLOGY. 

and low vegetation, often near marshy or boggy land in sandy 
districts. The eggs are sometimes laid in the edges of leaves, 
singly, between the upper and under surfaces, and are so thin 
that they can be perceived with difficulty only. They swell, 
however, very considerably before hatching. 

In New Jersey species of this genus sometimes do great injury 
on cranberry bogs, eating out the seed-capsule of the berries and 
rejecting the pulp. A single specimen may eat, at one meal, the 
seed-capsules of five or six berries, and in a week half a peck may 
be destroyed or rendered unmarketable. 

Turkeys exercise a good effect here also, the insects recog- 
nizing the presence of an enemy in a very short time and leaving 
the bogs. A good method of lessening the injury is to burn 
over the ground around the infested district to destroy the eggs. 
Nature itself does much to check increase, the number of speci- 
mens averaging about the same from year to year ; so any in- 
telligent interference by man must be to his advantage, and a 
destruction of the dropped leaves, especially of oak, which may 
contain eggs, will be a gain. 

Next in size and musical ability are the * ' cone-nosed grass- 
hoppers, ' ' Conocephalus, with very long antennae, very long hind 
legs, very long and narrow fore-wings, and a pointed, conically- 
projecting head. In the female the ovipositor is as long as or 
longer than the rest of the body. These insects may be quite 
common, yet rarely seen, because of their resemblance to the 
reeds, grasses, and other vegetation among which they live. 
They do not become active until late in the afternoon, and may 
be located by their loud, shrill, long-sustained song. Then, 
quietly waiting until it is resumed, the male may be seen with 
wings rapidly vibrating and usually near his mate, for whose 
benefit all this concert is produced. The eggs are laid in the 
stalks of the reeds and grasses among which the insects live ; 
hence late mowing of infested meadows, or burning over, during 
the winter, swampy or marshy spots in which they breed will 
keep them in check when they become troublesome. 

Close relatives of the above are the smaller, green meadow 
grasshoppers, largely members of the genera Orckelimum and 
Xiphidium, — the former with curved, the latter with a straight 
ovipositor in the female. These species all prefer moist lands 



THE INSECT WORLD. 



97 



with rank vegetation abounding in reedy grasses, in which they 
lay their eggs, and among which they sport and sing, except 
during midday. They are especially fond of eating the seeds of 
grasses, and sometimes become troublesome from this habit. 
The late mowing and burning suggested for Conocephalus will 
answer in this case as well. 

We find quite a departure from the normal type in a series of 
wingless or short-winged species erroneously called ''crickets," 
and, more correctly, "shield-backed grasshoppers." In the 
Eastern United States these are rare, found under stones or rub- 
bish in woods, sometimes in caves. Some are blind, and others 
have equally interesting structures, but are of little or no economic 
importance. From their peculiar humped shape some are known 
as "camel crickets." In the West these species become more 
abundant, and, at the base of the Rocky Mountains, extending 
up into the foot-hills, they find their true home. Here the 
"Mormon cricket," Afiabms simplex, occasionally multiplies so 
greatly that it migrates to the plains below, destroying everything 
in its path. As the insects are wingless they move but slowly, 
and may be often checked by ditching in their path. They are 
very pugnacious, with cannibalistic tendencies, falling upon and 
devouring any injured comrade, and indulging in free fights when 
driven into a corner. A plowed field in their course forms a 
barrier difficult for them to pass, and in such an army of the 
insects can be materially reduced or exterminated by means of 
heavy rollers. 

Yet more cricket-like are the clumsy, large-headed species of 
Stenopalmatus, known on the Pacific Coast, where they occur, 
as "sand-crickets." They are sometimes quite plentiful, but 
have not been known as injurious, since they are partly carniv- 
orous in their food-habit. 

The crickets belong to the family GryllidcB, and differ from the 
LocustidcE in that they have the wings laid flat on the back, 
the fore-wings abruptly bent down at the sides, and, in the female, 
have the ovipositor cylindrical or needle-like, instead of flattened 
or sword-like. This ovipositor usually has a little enlargement, 
somewhat resembling a spear-head, just before the tip, which 
facilitates placing the egg. The males are even greater musicians 
than the LocustidcB, the entire wing-covers being modified into a 

7 



98 



AJV ECONOMIC ENTOMOLOGY. 



stridulating organ. Here the sound is produced by the ridged 
edge of one wing-cover scraping over the ridged veins of the 
other, setting into vibration the membraneous spaces in both 
wings. The ear is situated on the fore-tibia, as in the LocustidcB, 



Fig. 69. 




A sand-cricket, Stetwpabnatus species. 



The mole-crickets are curious, subterranean creatures, with 
small heads and powerful forelegs, developed somewhat like the 
corresponding organs in the mole. The larger, more common 
species belong to the genus Gryllotalpa, and are more frequent 



Fig. 70. 




Mole-crickets, Gryllotalpa species. 



in the South and Southwest, where they occasionally injure field 
crops. They are strictly nocturnal in habit, and remain during 
the day in their burrows, in which a chamber is excavated to 
contain the eggs. 



THE INSECT WORLD. 



99 



When they are sufficiently numerous to be troublesome, the 
insects may be attracted to the sweetened and poisoned bran 
mixture heretofore mentioned, and this will usually check injury. 

The field-crickets, species of Gryllus, well known to all, are 
found nearly ever}^where, even in houses. They are usually dark- 
brown or blackish in color, with large, broad heads, and rather 
short though power- 



ful hind legs. They 
are very active, and 
jump about so errat- 
ically that it is not 

Fig. 71. 




Fig. 72. 




field-cricket, Gryllus 
species. 



1\\Q\.x&&-zx\c\iQ\. ,CEcanthus niveuii , female from 
the side, male from above. — a, blackberry cane 
showing egg punctures ; b, the same, split, to 
show the arrangement of the eggs ; c, egg, very 
much enlarged ; d, its tip, yet more enlarged. 



always an easy task to capture the specimens. There is less 
trouble in the fall, when the female is ovipositing in warm, sandy 
spots, and the male is watching her, keeping up a constant sing- 
ing during the operation. As a rule the species winter in the egg 
state, but occasionally nymphs and adults survive, and a solitary 
and melancholy chirp in spring now and then tells of such a speci- 
men. Most of the species are plant-feeders, yet rarely attack 



lOO 



AN ECONOMIC ENTOMOLOGY. 



green vegetation ; fruits like cranberries are occasionally eaten 
into, and sometimes roots or tubers are attacked ; but the injury 
is rarely of economic importance. 

Crickets are pugnacious as a rule, occasionally eating their 
companions, or such other soft-bodied specimens as fall in their 
way, while "cricket-fights" are not unknown in the lists of sports. 

The tree-crickets, CEca^ithus, are more slender and graceful 
than any of the preceding, and more ready fliers. They are 
green, yellowish, or gray in color, and live on trees or shrubs, 
feeding chiefly upon plant-Hce and other soft-bodied insects of 
various kinds. They lay their eggs in the stems of pithy plants 
like blackberry and raspberry, puncturing the wood by means of 
their powerful, auger-like ovipositor. Quite often these punctured 
canes die, but practically little damage is done unless the insects 
are much more abundant than I have ever seen them. In either 
blackberry or raspberry canes the punctures are so readily seen, 
especially in spring, that they can be cut out while trimming and 
the whole brood destroyed. This is indeed the best method of 
dealing with these graceful creatures, who have little resemblance, 
except in essential structure, to their lowly and sordid cousins of 
the field. 



CHAPTER V. 

THE HEMIPTERA, OR BUGS. 

The term Hemiptera means half-winged, and is primarily ap- 
plied to insects in which the wing-covers are partly thick and 
leathery and partly thin and membraneous, the latter texture 
obtaining towards the apex. The term becomes inapplicable, 
however, in those insects which, agreeing otherwise in structure 
with the half-winged species, have the anterior wings of the same 
texture throughout, whether like that of the hind wings or de- 
cidedly thicker. To distinguish the two series the terms Heter- 
optera, meaning "different wing," and Homoptera, meaning 
"equal wing," are applied. Besides these there is another 
division which has no wings at all, and, owing to the fact that 



THE INSECT WORLD. 



lOI 



the species live and feed upon animals, this is called Parasitica. 
All these agree, however, in the essential character of the order, 
which is found in the structure of the mouth parts. Throughout 
all series we find the head prolonged into a jointed beak or ros- 
trum, obsolete only in the Parasitica, and within, protected by- 
it, is a series of three or four slender, needle-Hke lancets. The 
beak is open in front, and the lancets may be protruded at the 
tip. In most species, when the insect is feeding, the lancets are 
so deeply inserted that the beak bends at or about the middle, 
leaving them entirely free except at the tip. In other cases, 
among predaceous types, the beak is too rigid to bend thus, and 
it, as well as the lancets, is forced into the tissues upon which 
the insect feeds. It is to insects of this order only that the ento- 
mologist applies the term biLg'^ and when he uses that word 
he always refers to one of the Hemiptera. It has been indicated 
that the creatures gain their food by piercing and sucking, and 
this is a radically different method from anything found hereto- 
fore. We have now insects that are incapable of chewing food, 
and subsist only upon liquids which must be drawn from living 
tissue, be it animal or vegetable. A large proportion of the spe- 
cies is injurious ; but there are also groups of predaceous habit, 
feeding upon other insects in whole or in part, that may be con- 
sidered beneficial. In their development the insects belong to 
that series in which the metamorphosis is incomplete ; but there 
is an exception in the males of certain bark-lice, where there is a 
real, quiescent pupal stage 

Before going further on this subject it is necessary to refer to 
the peculiar little species known as Thrips, and belonging to the 
family ThripidcB. They are now as a rule, and properly, sepa- 
rated from the true He77iiptera under the ordinal terms Thysan- 
optera, meaning fringe-winged, or Physopoda, meaning bladder- 
footed. They are always small in size, slender, active, with the 
head so narrow that they seem pointed at both ends. The wings 
are laid longitudinally on the back, and are very narrow, trans- 
parent, without veins or with mere rudiments, but with lengthy 
fringes, which give them a characteristic and peculiar appearance. 
The feet are not terminated by pointed claws as usual, but by 
small, bladder-like dilations of the terminal joints. They run 
and fly readily, and some of them jump much as do spring-tails. 



I02 AN ECONOMIC ENTOMOLOGY. 

The mouth structure is in some respects intermediate between 
that of the true bugs, as already described, and that of the man- 

dibulate type ; but there are no 
true mandibles, and the insects can- 
not chew their food, hence come 
naturally, for our purpose, into this 
order. 

The species of Thrips are often 
seriously injurious to vegetation. 
They sometimes attack onions in 
great numbers, puncturing the suc- 
culent leaves, and everywhere leav- 
ing a small yellow dot. As these 
increase in number the leaf loses 
vitality, the top itself turns yellow, 
and in serious cases the rich green 

Thrips tritici.—b, antenna ; c, a tarsus, of a normal Ouion field is changed 

to a peculiar, sickly yellow. The 
insect is yellowish when immature, and blackish-brown when the 
wings are developed. 

Cabbages sometimes suffer in a similar manner. The insects 
in this case are yellow, and congregate in large numbers on the 
lower side of the outer leaves, and as these become dry and 
wither they move to those nearer the centre. 

Grass is often attacked by them, and here they cause one 
form of what is known as "silver top." Wheat, oats, rye, and 
other grains are often victimized, and, indeed, there are few 
plants not liable to infestation, even tobacco appearing among 
the sufferers. 

These insects thrive best in hot, dry weather, hence become 
more dangerous as the plants are less able to resist them, and 
our effort must be in the direction of aiding the crop as well as 
destroying the insects. Contact poisons are indicated here, as 
against the true Hemiptera^ and either the kerosene emulsion, 
diluted ten times, or the whale-oil soap, one pound in four gal- 
lons of water, is satisfactory. Plenty of cold water, where it is 
available, acts very well on a small scale ; but no application is 
feasible on large fields of cereals or grass. Here stimulation only 
can be resorted to to give the plants additional vigor, and har- 



FiG. 73- 




THE INSECT WORLD. 



vesting should be done as soon as possible to check the increase 
of the pests. 

Many species of Thrips are found on flowers, many also under 
the bark of trees, and some forms are said to be predaceous. 
Their life habits are not well known, but a large number winter 
in the adult stage under such shelter as they can find, — hence, 
cleanliness on the farm is indicated. 

For a better understanding of the characters of the more typi- 
cal He77iiptera, we will take up the families separately ; and first 
the Parasitica. By taking up this series before the others it is 
not to be understood that they are higher in the scale, nor, on 
the other hand, much lower in type ; but it is simply a matter 
of convenience. Parasites, because of their habits, are often said 
to be "low ;" but it is a question whether this is true, because 
parasitism is an acquired character, and the insects are really 
much specialized for their habit of life and well adapted to it. 
We have in a previous chapter considered the biting lice, and 
found that they feed more particularly upon surface structures. 
The sucking lice, as the term indicates, obtain their food by 
piercing the skin and sucking the animal juices or blood. The 
mouth differs from that of the other bugs in that the proboscis 
is fleshy and unjointed, capable of being withdrawn into the head 
or extended, and within it are two protrusible lancets only. At 
its base is a circlet of hooks, by means of which the insect an- 
chors itself firmly in the skin of the infested animal. The legs 
are " scansorial," or fitted for climbing, — that is to say, they are 
short, heavy, set at the sides of the thorax, and the tarsus is 
modified into a stout, slightly curved claw, opposed like a thumb 
to the end of the tibia, which in turn is broadened at the tip and 
a little excavated. Thus, between the end of the tibia and the 
tarsus, the insect is able to grasp a hair so tightly that it is some- 
times easier to pull it from the skin than to dislodge the parasite. 
Here we have another example of insects that do not change in 
appearance throughout their life : they simply increase in size 
and become adult when the sexual organs are fully developed. 
Warm-blooded animals only are infested by these sucking lice, 
man being included under this general term. 

Three species are found on the human animal: one, Pedicuhis 
capitis, infesting the head, glues its eggs, which are known as 



104 



AN ECONOMIC ENTOMOLOGY. 



Fig. 74- 




Hog-louse, Hizmatopvius urius : the scansorial claw at c. 




l^HE INSECT WORLD. 



*'nits," to the hair; one, Pediculus vestime7iti, found on the 
body, known as the ' ' body-louse, " or to soldiers as ' ' gray- 
backs, ' ' lives in and lays its eggs in the seams of clothing, where 
they are protected ; the last, Phthirius ingzcinalis, known as the 
"crab-louse," infests the pubic region and armpits. The latter 
fastens its eggs to the hair among which it lives, and this is per- 
haps the general rule throughout the series. 

Domestic animals of all kinds are infested by lice ; but it is not 
necessary to study the species in detail, since their habits are 
much the same, and the method of treatment is identical. For 
the head-louse on man nothing is better than a thorough appli- 
cation of lard, vaseline, or other greasy material. It should be 
applied at least twice at intervals of a few days, because the treat- 
ment does not kill eggs, and eggs unhatched at the first treat- 
ment would not be affected. 

As against the body-louse, the application of mercurial oint- 
ment in the seams of the clothing answers every purpose. This 
has proved effective in camps and hospitals, where the insects 
sometimes increase with marvellous rapidity. 

As against the "crab-louse," the mercurial ointment may be 
applied directly to the infested spots, and here also several ap- 
plications are necessary to reach 
the insects as they hatch from the Fig, 76, 

eggs. Their vitality is great, and 
that of the eggs is yet greater. 
Clothing, no matter how carefully 
washed, may still remain infested 
with eggs, protected as they are 
in the seams, unless actual boiling 
is continued for a considerable 
period of time. Where lice infest 
animals the latter can sometimes 
be cleared by simply giving them crab-iouse, Phtiurius ingumaiis. 
an opportunity to dust themselves. 

Dogs, donkeys, less frequently horses, and other animals, may 
be often seen in dusty roads, rolling about in evident enjoyment, 
and one result of this powdering is a comparative freedom from 
insect parasites for some time thereafter. Infested animals may 
be treated as suggested for the head-lice in man, — that is, some 




io6 AN ECONOMIC ENTOMOLOGY. 

heavy oil or grease should be applied thoroughly. It will add 
to the effect of the mixture if a little carboHc acid is added, but 
it is not essential, though desirable to prevent rancidity if animal 
fat is used. The kerosene emulsion, used with a brush or curry- 
comb in cleaning animals, is also effective ; in fact, the treatment 
suggested for the biting lice is also applicable here. 

The section Homoptera contains scale-insects, bark-lice, mealy 
bugs, plant-lice, tree-hoppers, leaf-hoppers, frog-hoppers, and 
others whose very names proclaim their character. Nowhere do 
we find predaceous forms, or such as can be accounted beneficial 
to the agriculturist. To be sure, we have among the Coccids the 
cochineal and lac insects, but these are fully as injurious as any 
other to plant life, and are useful simply because man is able to 
make better use of them than of the plants upon which they feed. 

The family Coccidcs includes scale-insects and mealy bugs, cu- 
rious in their life history as well as injurious to cultivated plants. 
The males, unlike other Hemiptera, have a complete metamor- 
phosis and only a single pair of wings, the secondaries disap- 
pearing or reduced to mere hooks. They are singular, fur- 
thermore, in that the mouth parts are replaced in the adult stage 
by a pair of eyes. The female is always wingless throughout her 
entire life, generally grub-like and stationary, covered with some 
sort of waxy scale or by a powdery or cottony secretion. 

Mealy bugs derive their name from the fact that they are cov- 
ered by a white, powdery substance, which is really a granulated 
wax and a secretion of the insects themselves. They move about 
freely, and are furnished with all sorts of odd processes at the 
sides of the body, or with long filaments at the end. They are 
not usually common in the North except in greenhouses and on 
in-door plants, but become more abundant southward, where out- 
door plants are also infested, orange-trees in Florida being par- 
ticularly troubled. To this series of mealy bugs the cochineal 
insect, Coccus cacti, belongs. It is a native of Mexico, but has 
been cultivated in other countries, feeding upon species of cac- 
tus. Specimens have been found in Florida, and it is more than 
likely that it occurs not uncommonly in the semitropical part of 
the peninsula. It also occurs in California. The dye is simply 
the immature female insect, which is brushed off the plants, 
killed, and dried, and has never been equalled for brilliancy and 



THE INSECT WORLD. 



107 



Fig. 77. 




Cochineal and mealy bugs.— Fig. 77, cochineal, Coccus cacti, on cactus. Fig. 78, 
b, adult male ; c, adult female, with cottony masses removed. Fig. 79, mealy bug, 
Dactylopius destructor. Fig. 80, Dactylopius longifilis : a, the larva ; b, the winged male. 



io8 



A^' ECOXOMIC EXTOMOLOGY. 



permanence. Aniline dyes and colors are superseding it. how- 
ever, because of their cheapness and the greater ease with which 
they may be obtained. 

Mealy bugs are easily destroyed by contact poisons, almost 
any soapy solution killing them readily. A ver}- dilute kerosene 
emulsion answers ever}' purpose, and even a weak salty solution 
is satisfactor}\ I have used both kainit and muriate of potash 
dissolved in water at the rate of an ounce in a quart, and it has 
been perfectly effective where entire plants have been dipped into 
it, A tobacco decoction, one pound in one gallon of water, is 
also useful, and not dangerous to the most delicate plants. Where 
house-plants are troubled the tobacco water is ver}^ convenient, 
or common insect-powder may be used at the rate of an ounce 
in two quarts of water, and sprayed on with an atomizer. Where 
applications are to be made on a large scale, the diluted kerosene 
emulsion is the most satisfactory, one part in fifteen of water be- 
ing ordinarily sufficient. 

Next comes a series where the excretions are in the form of 
waxy scales, which sometimes become hard, brittle, and beauti- 
fully ribbed. The female forms a sort of sac of these waxy scales, 
and in it the eggs, mixed with a very fine powder, are contained. 
This type is also rather more common southwardly or in warm 
countries, the few species that occur in the North being rather 
scarce and generally confined to weeds. The " cotton}^ cushion 
scale," Iceiya piirchasi. which has caused such injury in Cali- 
fornia, belongs here, and we have several allied species in Florida, 
and yet more in the W est Indies. All these insects gain their 
food by sucking the plant juices, and their power of injur}' is 
magnified b}^ their enormous productiveness. 

Perhaps this is a good place to speak somewhat at length on 
this ' ' cotton}' cushion scale, ' ' and the micasures taken against it 
by introducing foreign predaceous species. The very remarkable 
success that has attended the introduction of " lady-birds" 
(Coccinellidae) from Australia has led many persons to the belief 
that insects of similar character might be introduced from other 
countries to deal with some of our native species, and much 
time has been wasted and some money spent by ill-considered 
schemes of this description. The factors that caused success in 
the case of the Iceyya were : ist, an insect introduced from a 



THE INSECT WORLD. 



109 



foreign country where it was on the whole rather scarce and kept 
in check by natural enemies ; 2d, its introduction into America, 
where these natural enemies did not exist, and where the insect 
found favorable opportunity for multiplying ; 3d, the introduction 
of some of its foreign parasites and of the predaceous insects 




feeding upon the species ; lastly, and most important of all, the 
Australian lady-bird recognized no other insect among those 
found in California as proper food, and naturally confined itself 
entirely to these scales. The contest was unequal, and the scales 
lost rapidly, soon becoming nearly or quite exterminated. The 



no 



A A' ECONOMIC ENTOMOLOGY. 



chances are now that the lady-birds will follow them and become 
scarce or extinct, unless they show the power of adapting them- 



treatment becomes exceedingly expensive and practically useless. 

A curious series of species is found in the genus Kermes , often 
found on oaks, and resembHng at first sight galls or even small 
snail-shells, their texture being almost as brittle as if composed 
of lime. They are never economically important, but curious 
enough to deserve mention here. 

Next come what are known as " soft scales," usually of con- 
siderable size and readily visible. Quite commonly they are 
convex or nearly hemispherical, rarely quite regular in outline, 
and sometimes ribbed or ridged. In most instances they are 
brown in color, not very rigid in texture, and easily crushed ; 
whence the term " soft scales." We have a number of injurious 
species, and perhaps none more common than the ' ' cottony 
maple scale, ' ' Pzilvinaria innumerabilis . Though called the maple 
scale, and found most frequently on that tree, yet it is by no 
means rare on grape, and often common on the Virginia creeper. 
Sometimes it occurs on other plants as well, and is occasionally 




Icerya purchasi, female. 



Fig. 82. 



selves to surroundings, and 
find other food to their likino^ ; 
but while they have been use- 
ful as against the Ice?ya, and 
may have entirely destroyed 
it, we cannot hope that they 
will be equally successful in 
coping with our native insects, 
who have long since adapted 
themselves to their surround- 
ings in such a way as to make 
it unlikely that any intro- 
duced species will be effectual 
in seriously lessening their 
numbers. Insects of this char- 
acter are susceptible of treat- 
ment with the kerosene emul- 
sion, although, where they 
occur in such numbers as did 
the Icerya in California, this 



THE INSECT WORLD. 



Ill 



numerous enough to require treatment. It usually attracts atten- 
tion in spring, when white cottony masses become numerous on 
twigs or leaves, increasing in size until they are one-fourth of 
an inch or more 

in length, and only Fig. 83. 

slightly less in diam- 
eter, though irregu- 
lar in outline. The 
mass seems cottony, 
but is actually a wax 
or gum, for, if a bit 
is taken with a for- 
ceps it can be drawn 
out into strings of 
considerable length. 
When of this size it 
forms a bedding for 
innumerable, rusty- 
brown, minute eggs, 
which have been 
laid by the female 
insect under the 
brown scale which 
seems to form the 
head of the mass at- 
tached to the twig. 

From these eggs minute, crawling larvae hatch, much like the 
eggs in color, and which separate in every direction in what seems 
to be a moving mass of fine dust particles. In a day or two each 
lar^'a inserts its beak into a leaf or twig, and commences the for- 
mation of a little, flattened, oval, somewhat mottled scale. They 
remain thus, feeding and increasing in size, and as they increase 
the scales enlarge. The males come to maturity in the latter part 
of the summer, appearing as minute, two-winged flies, furnished 
with long anal filaments. They mate with the females which re- 
main under the scale, and these, before the leaves fall, migrate to 
the twigs or branches, where they fasten themselves to pass the 
winter. Feeding is resumed in spring, when the sap begins to 
circulate, and then the egg masses begin to form. Before the 




Cottony maple scale, Pulvinaria innumerabilis , showing, at 
a, the female on a leaf and, at b, same on a twig. 



TI2 



AN ECONOMIC ENTOMOLOGY. 



cottony secretion becomes visible the female scale is less than 
one-eighth of an inch in length, very convex, a little irregular, 
and mahogany-brown in color. As the egg mass increases in 
size the scale is lifted posteriorly, until finally the insect adheres 
only by its beak and by the sticky nature of the cottony mass. 



Fig. 84. 




Cottony maple scale.— c, leaf covered with scales ; 5, male scale ; c, adult male. 



We have other species of similar character in which there is 
no cottony mass protecting the eggs, but the life history is essen- 
tially the same. These ' ' soft scales' ' mostly belong to the genus 
Lecanium, and are much more common southwardly and in con- 
servatories. Citrus fruits and olives are especially subject to 
soft-scale attack, and the ' ' black scale, ' ' Leca7iium olecz, is in 
California the most troublesome of all and the most injurious. 
In the genus Ceroplastes the scale is formed of waxy layers, 
sometimes quite pretty in pattern. These are found only in the 
extreme South, and are not especially troublesome. 

The matter of remedies will depend entirely upon circumstances. 
On garden plants or shrubs the scales may be mechanically 
removed during the winter. They do not adhere closely, are 
easily dislodged, and are of a size sufficient to be readily seen. 
Not all, however, pass the winter in the adult condition. In some 



THE INSECT WORLD. 



cases, instead of a female, an egg mass will be found beneath the 
scale ; but in either case mechanical dislodging results in the de- 
struction of the insects. 

Very often a little judicious ^5- 
pruning or trimming, done 
during the winter, will give 
relief, because the insects 
usually settle on the termi- 
nal twigs, and it might 
easily be that none of the 
larger branches contained 
living scales or eggs. In 
conservatories the mechan- 
ical method is, all things 
considered, the best. It 
may take a little more time, 
but it is thoroughly effect- 
ive, and when carefully 
done there may be almost 
total exemption until scales 
are again introduced with 
new plants. 

This is a good place to 
say that no plant should be 
placed in a garden or con- 
servatory until it has been 
thoroughly cleaned of all 
scales found on twig or fo- 
liage, and a soft tooth- or 

hand-brush, with moderately strong soapsuds, forms a good outfit 
for doing the work. Where winter treatment is inadvisable or 
impossible, applications should be made when the larvae emerge 
from the eggs and before they fasten themselves to leaves or 
twigs. There is no difficulty in killing the young with either 
soapsuds or kerosene emulsion, but — and here is the important 
point — the application must be made before the insect is pro- 
tected by a scale, or when the scale is yet very thin and newly- 
formed. Kerosene will penetrate the waxy mass of the maple 
scale, but it will not certainly kill the eggs contained in it ; yet 

8 




Lecanium hemisphericum, on orange-leaves, nat- 
ural size ; a, female scale, enlarged. 



114 



AiV ECONOMIC EXTOMOLOGY. 



if soapsuds be used to dilute the emulsion, instead of water, the 
cottony mass will be so impregnated with soap, and become so 
compact, that the young will be unable to make their way out. 
Therefore, in this case, dilute three quarts of kerosene emulsion 
with one pound of whale-oil soap dissolved in eight gallons of 
water. 

The most troublesome of all scale insects belong to the Dia- 
spincB^ or "armored scales," and these are generally small in 
size. They are, as a rule, only a little convex, occasionally even 
flattened, and in texture are more like membrane or parchment 
than wax. All kinds of shapes occur, and there is considerable 
variation in life history. In one point they all agree, — after the 
active larvae have once become fixed and covered with a scale, 
they never leave their position, except when the males emerge 
as adults and visit the surrounding females. In general the life 
history of the insects is as follows : the larvae, whether hatched 
from the eggs or born alive, crawd about for a fe\v hours, or at 
most a day or two, seeking a convenient place to fix. • They are 
always minute, flattened, oval creatures, with six legs, a pair of 
distinct feelers, and a curious, long, sucking mouth. This is 
soon inserted into the plant tissue, and from that time the insect 
is a fixture. Little waxy filaments begin to exude from the body, 
w^hich soon coalesce, or run together, forming a first covering or 
scale over the soft larva. The insect soon moults, and the cast 
skin forms part of the scale, the resulting creature being legless 
and without power of motion. There is one additional moult, 
after which the sexes are very diflerent in appearance. The male 
shows antenna, legs, and wings well marked, and is indeed a 
perfect pupa, while the female is even more grub-like than before, 
rudiments of antennae only being visible. The second cast skin 
of the female also forms a part of her scale, and there is nearly 
always some difference in shape between the sexes, the male 
being not only smaller, but narrower. Shortly after the change 
to the pupa the male becomes adult, and in this series has the 
end of the abdomen prolonged into a style or pointed process, 
sometimes equalling in length the rest of the insect, though 
usually shorter. Antennae and wings are both prominent, and 
as a whole the insect is curious and exceedingly fragile in appear- 
ance. Its life is probably short, though long enough to accom- 



THE INSECT WORLD. 



plish its mission, — the fertilization of the female. After this the 
life histories differ greatly ; sometimes the female lives through 
the winter in the partly-grown or adult condition ; sometimes she 
lays eggs which fill up the entire space beneath the scale, the 
insect itself shrivelling up until scarcely a trace remains. Some- 
times living young are brought forth, and there may be one or 
several broods. Hence it is necessary to study each species in 
detail before we can say much on the subject of remedies. It is 
obviously beyond the province of this book to describe all the 
injurious species, and general statements only are possible. 



Fig. 86. 




Oyster-shell scale, Mytilaspis poniorum. — a, female scale, from beneath, filled with 
eggs ; b, same, from above ; c, twig infested by female scales ; d, male scale and a twig 
infested therewith. 

Perhaps the most common forms of this series are the ' * oyster- 
shell" bark-lice, of which we have several species, deriving their 
common name from the fact that the scales have a marked resem- 
blance to the shells of some oysters. In the Northern United 
States Mytilaspis pomorum is the common form, infesting apple 



ii6 



AN ECO ATOMIC ENTOMOLOGY. 



and other fruit trees, willow, lilac, and a great variety of other 
plants. It is perhaps uncertain whether all are really one species, 
but for our present purpose we may consider them so. There is 
one brood only, and they winter in the egg state, the larv^ 
appearing in spring, the time depending upon the weather. In 
the South there may be two broods, but I believe that there are 
few exceptions to the rule that wintering takes place in the egg 
stage. On orange and other citrus plants we have species closely 
resembling that on the apple, and not distinguishable except on 



Fig. 87. 




Mytilaspis pomorion. — a, male ; b, its tarsus ; c, young larva ; d, its antenna ; e, female. 

close examination, even by the specialist. These scales some- 
times cover twigs and large branches completely ; even the leaves 
are often infested, and not infrequently the fruit itself becomes 
more or less covered. It is not unusual to see in market oranges 
and lemons more or less spotted by these oyster-shell scales, and 
I have seen lemons from Mediterranean countries with the skin 
almost entirely hidden by them. 



THE INSECT WORLD. 117 
Fig. 88. 




The San Jos^ scale : winged male above ; c, young larva, just hatched ; b, its antenna ; 
c, female, showing the forming young through the body wall ; d, outline of anal plate 
of female : all very much enlarged. 



Ii8 AN ECONOMIC ENTOMOLOGY. 

In our treatment of these insects we must either apply exceed- 
ingly caustic winter washes, to corrode the scale and allow the 
eggs to be washed out by rain or destroyed by other climatic 
influences, or we must apply contact insecticides when the eggs 
hatch or the larvae emerge from beneath the scales. 

Some of our destructive species belong to the genus Aspidiotus, 
and these have the scale nearly circular in outline, with the rem- 
nants of the cast larval skins showing through at or near the 
middle and forming a sort of nipple-like prominence. The male 
scales are decidedly smaller than those of the female, and some- 
what more oval or oblong. The ' ' red scales' ' of the orange in 
California and in Florida belong to this genus ; but perhaps the 
most troublesome of all is the A. peryiiciosns , or San Jose scale. 
As this species is now widely distributed and very injurious where 
it occurs, its life history may be given in some detail. 

The insect winters on the infested trees in the larval state, and 
usually about half grown, both sexes being found. Males mature 
soon after spring opens, — in the latitude of Philadelphia, about 
the middle of May, but depending somewhat upon the season. 
Toward the end of that month the females become fully devel- 
oped, and begin to bring forth living young. That is to say, the 
species is viviparous, and produces no eggs. The larvae do not 
differ essentially from those of other scales, and fix in from twelve 
to thirty-six hours, depending somewhat upon circumstances. 
At that time a thin white pellicle forms, which soon turns yellow, 
and a little later becomes gray around the edges. The insect is 
then a fixture, and continues its growth much as previously 
described, but reaches the adult condition, and is ready to repro- 
duce, in a little more than a month. This short period enables 
it to mature several broods, and during the entire summer, and 
until late fall, reproduction continues, — the broods becoming 
mixed, and all stages being present continuously upon the plants 
soon after summer opens. With such a life history the insect is 
exceedingly difficult to control, and practically we are reduced to 
winter work, as will be hereafter pointed out. The scale infests 
all the usual deciduous fruit-trees, roses, currants, gooseberries, 
— in fact the entire order Rosacecs, and occasionally occurs on 
chestnut, walnut, and elm. It is probable that yet other plants 
are subject to infestation, and this omnivorous habit and the 



THE INSECT WORLD. 



119 



wonderful power of reproduction make the scale especially dan- 
gerous. 

In the genus Diaspis the scales are more oval, and the cast 
lar\-al skins are at or near the margin rather than toward the 
middle, while the 

males are long and Fig. 89. 

slender. A common 
example is the Di- 
aspis ros(Z, found 
on roses and other 
plants belonging to 
the same natural 
family. The scale 
is pure white and 
very conspicuous, 
measuring nearly an 
eighth of an inch in 
diameter. 

Yet more oval, 
with the cast larval 
skins at the smaller 
extremity, are spe- 
cies of Chionaspis, 
and a good exam- 
ple is the ' ' scurfy 
scale, ' ' C. furfu- 
rus, common on 
pear and apple. A 
similar species is 
found on pine and 
spruce throughout 

the United States. These species may have one or two gener- 
ations, according to latitudes, but ususally winter in the egg state. 

Some of the species have the curious habit of boring under 
bark, thus passing a large part of their life out of sight, becoming 
more dangerous by that fact, since trees may be badly infested 
and the cause of sickness not even suspected by the farmer. 

It is practically impossible to even mention all the injurious 
scales of house, conservatory, or orchard plants, and it is not 




San Jos^ scale on a California pear, natural size ; the scale 
itself enlarged at b. 



I20 



AN ECONOMIC ENTOMOLOGY. 



really necessary, since the treatment to be adopted is nearly the 
same in all cases. On deciduous trees, where the scales remain 
during the winter upon trunks and branches, and where the trees 
become dormant, the scales are best treated during the winter. 
At that time there is no foliage to interfere, and we can use much 
stronger washes than would be safe during the summer, or when 
the tree is active. I have already called attention to the fact that 
it is difficult to penetrate insect tissues with ordinary liquids, and 
it has been found impossible in practice to obtain good results in 
the destruction of scale insects except by means of caustics. 



against the scurfy scale, while common laundry soap has been 
efficient against others of the softer species. The common soaps 
are all caustic, and, when applied at the strength indicated, the 
scale is shrivelled, lifted, and partially corroded, so that the oily 
mixture works its way beneath, into absolute contact with the 
insect. Or it is raised at the edges and washed off by the rains, 
carrying with it either eggs or young, as the case may be. In 
fact, where the eggs hibernate winter applications act only by 
exposing them, so that they are easily washed away by rains and 
scattered, under no proper condition to hatch. Or, should they 
hatch, the larvae are able in rare instances only to get upon the 



The scurfy scale, Chionaspis fiirfuriis. — a, twig 
infested by female scales ; b, with male scales ; c, 
female; d, male scale, much enlarged. 




Fig. 90. 



Potash and soda have 
been used wath good effect 
even in a simple watery 
mixture, but more satis- 
factorily in the form of 
very caustic soap. Whale, 
or other fish-oil soap, at 
the rate of two pounds in 
one gallon of water, as a 
winter wash, has proved 
absolutely effective against 
the San Jos6 scale and the 
oyster-shell bark-louse, 
two of the most resistant 
of the armored scales. 
The simple muriate of 
potash used as a fertil- 
izer has proved effective 



THE INSECT WORLD. 



121 



proper food-plant. In the case of plants which do not lose their 
foliage at any period, or in conservatories, or where winter treat- 
ment for any reason is not feasible, we must attack the insects 
when the larvae are crawling about, and before they are fixed. 
At that time, while not protected by a scale, they may be easily 
killed, almost any of the contact insecticides being effective. 
Soapsuds, a dilute kerosene emulsion, or a mixture of both, are 
satisfactory, and a good formula is : kerosene emulsion one part, 
soapsuds ten parts, the suds being of the strength of one pound 
of soap to six gallons of water. Whale or other fish-oil soap is 
better than common laundry soap, and the latter is better than 
high-grade articles containing only a minimum amount of caustic. 
This would not hurt any except very delicate plants, while it 
would be absolute death to larval scales. It is useful in the con- 
servatory on palms, which are often much infested, and for some 
of these it might be well to reduce the amount of kerosene to 
one part of the emulsion with from twelve to fifteen parts of soap- 
suds. Where the insects are viviparous, or bring forth living 
young, the spraying must be done systematically, at intervals of 
four or five days, until no more young appear. On out-door 
plants the same mixture may be used, but the spraying, if the 
larvae come from eggs, need not be done more than twice, since 
as a rule the eggs hatch at about the same time. On the Pacific 
Coast lime, salt, and sulphur mixtures, and various resin washes, 
have proved effective, but they are troublesome to make, and 
hardly cheaper, all things considered, than the soap mixtures 
above referred to. They act largely by sealing the scales to the 
tree, so that the young cannot emerge or the adults are stifled ; 
hence they are most effective where rains are few and far between. 
The formulae for their preparation will be found in the chapter on 
insecticides, where their range of usefulness is also stated. 

The species belonging to the family Aleyrodidce resemble 
scale insects in the immature condition, but are not fixed to the 
plants, and in the adult stage both sexes are winged, somewhat 
resembling minute plant-Hce. The striking character by which 
they may always be recognized is a covering of white, flour-like 
powder, which renders them easily visible upon the leaves. 
They are not common on out-door crops in the North, but are 
not infrequent on house or conservatory plants, becoming more 



122 



AN ECONOMIC ENTOMOLOGY. 



abundant and correspondingly more troublesome southward. A 
species sometimes occurs in considerable number on orange. As 
the insects live exposed in all stages, they are easily reached by 
contact poisons, and of these the kerosene emulsion is usually the 
most satisfactory. It kills them in all stages at moderate strength. 




one part of emulsion in ten or twelve parts of water being ordi- 
narily sufficient. Whale-oil soap is quite as effective, and is 
preferable on some house or conservatory plants, while even the 
pyrethrum extract is useful on a small scale, and is, perhaps, the 
cleanest of all on house-plants. 



THE INSECT WORLD. 



123 



It is a short step from the Aleyrodidce to the plant-hce, be- 
longing to the family Aphididce. Plant-lice are well known to 
agriculturists by the injury they cause, and they are interesting 
to the naturalist from their life history. Here we have the most 
striking apparent exception to the general rule that insects are 
developed from eggs, and yet perhaps the exception is more 
apparent than real. At all events, parthenogenesis, or repro- 
duction without the intervention of a male, occurs normally in a 
large percentage of the species. Of course there are many differ- 
ences in hfe habits, but a general account, covering most of the 
cases, is all that can be attempted here. As a rule, plant-lice 



Fig. 92. 




c, female hop-louse, shov/ing eggs through skin ; b, the stem-mother that starts the 
transformation ; much enlarged. 

winter in the egg stage ; but this is subject to many exceptions, 
especially in the warmer parts of the country. Early in spring, 
as soon as there is a trace of reviving vegetation, these eggs 
hatch. The insect that now appears is wingless, and usually 
remains so, but grows rapidly by sucking the plant juices, and 
soon begins to produce living young. It is called a ' ' stem- 
mother," because it is the source from which numerous genera- 
tions issue during the season. All the young born by this stem- 
mother are, like herself, without sex ; that is, they are neither 
males nor sexually-developed females. The rate at which they 
are born varies, but as many as eight living young have been 



124 



AN ECONOMIC ENTOMOLOGY. 



observed within a period of twenty-four hours from one specimen, 
and it is not unusual to find, early in the season, a single large 
louse surrounded by a group of anywhere from a dozen to 
twenty or even more small specimens. The rate of growth also 
varies, depending upon the weather ; indeed weather conditions, 
early in the season, frequently determine the question of whether 
or not certain species are to become injurious later on. A warm, 
moist temperature favors their development, and reproduction 
goes on at a rapid rate. Correspondingly, cold, wet weather 
checks development, and may even destroy a large number, 
especially of the young. Plant-lice, in their younger stages, are 
exceedingly susceptible to sudden changes of temperature, and 
at almost any time in the season a sudden drop of from fifteen to 
twenty degrees, accompanied by a rain, will prove fatal to a great 
proportion of them. But assuming that all is favorable, the 
young that were first brought forth are in turn ready to repro- 
duce in five or six days, and they also form little colonies ; this 
method of reproduction continuing as long as food is plenty and 
the weather mild. Experimentally, reproduction of this kind 
has been continued for several years in succession, without any 
tendency to develop sexed individuals or to produce eggs. At 
almost any time after the first generation, specimens may become 
winged, and these fly to other localities, forming new colonies 
wherever suitable food is found. In this way they spread, and, 
though they may have started from a single favorable locality, 
yet in the course of a few weeks they may cover many hundreds 
of acres. Exactly what determines the formation of wings in 
some specimens and not in others is not known. We do know, 
however, that the progeny of a single individual is variable, and 
that while some become winged others do not ; but whether 
winged or wingless, the specimens are equally without sex, and 
all are viviparous, or bring forth living young. As the summer 
advances, reproduction becomes less rapid. Plants tend to dry, 
the supply of sap is not so plenty, and these features become 
more marked through the autumn months until, with the ap- 
proach of cold weather, plant growth entirely ceases. It becomes 
necessary now to provide for the continuation of the species 
during winter, and sexed forms are developed. The males are 
winged and usually appear a short time before the females, which 



THE INSECT WORLD. 



differ by the lack of wings and tlie usually small size compared 
with the normal sexless form. Pairing takes place almost imme- 
diately, because the female is sexually mature when born, and 
shortly afterwards eggs are laid. In many instances the egg 
supply is exceedingly small, indeed there may be one only ma- 
tured by a female. Even this may remain within the body of the 
parent, who simply dries up, the skin shrivelling around and 
forming a protection to the ovum. More usually several eggs 
are produced, and these of large size in proportion to the size of 
the insect that lays them. They are green or greenish-brown 



Fig. 93. 




Hop-louse, male ; return migrant. 

in color when laid, sometimes yellowish, and frequently darken 
to black. They are placed in sheltered situations on plants, and, 
in the case of orchard trees, are usually found at the tips of twigs, 
around the buds, or on the leaf-scales, where vegetation will first 
start in the spring following. They are very firm in texture and 
very resistant to insecticides ; in fact, it is impossible to destroy 
them except by the most caustic mixtures. It has been already 
indicated that there are many exceptions to this general life his- 
tory, and one kind of exception we find where species feed dur- 



126 



AN ECONOMIC ENTOMOLOGY. 



ing the summer upon a plant which dies down to the ground, 
leaving nothing through the winter. In such cases there is an 
alternate food-plant, upon which the winter and early spring are 
passed. From this the insects migrate in early summer and to 
it they return when cold weather sets in. Such a case we have 
in the hop-louse, which spends the summer upon the hop, in- 
creasing greatly in number in favorable seasons and often causing 
much injury. When the vines mature and die, males develop, 
and all the lice fly to plum-trees. Here the female is born, the 
sexes mate, and eggs are laid. In the spring two or more gen- 
erations mature upon the plum, and, when the vines are again 
well started, winged forms develop and migrate to their summer 
food-plant. This sort of migration is not unusual, although it 
has not been traced out in many cases. 

Another example we find in the "melon-louse," which has a 
considerable range of food-plants, including cotton, orange, 
strawberry, and nearly all the common weeds of our fields. If 
circumstances favor their increase in spring, winged forms are 
produced which migrate and settle upon melon fields, providing 
for colonies during the summer. 

The scientific problems connected with this method of repro- 
duction and spread are of great interest, but cannot be entered 
upon here ; the mere statement of the case being sufficient for 
practical purposes. Plant-lice are so commonly known that a 
detailed description of their appearance is unnecessary ; but it is 
well to call attention to the presence of a pair of little tubes or 
cornicles near the end of the abdomen, projecting from the upper 
surface. These are called honey-tubes, and from them is excreted 
a sweetish liquid known as honey-dew. Sometimes,, when food 
is abundant and the insects are active, the amount of sap they 
pump out of the plants is so great that, in order to ease them- 
selves, they void it in little streams through the anus, as well as 
in drops through the honey-tubes. Thus the leaves of infested 
plants become sticky or glazed with a sweetish liquid, on which 
a black fungus rapidly develops, the leaf being frequently killed 
by simply choking to death. Sometimes the vegetation beneath 
a tree becomes thoroughly coated in the same way, or, when 
shade-trees in cities are infested, the pavement becomes wet and 
slippery with the viscid liquid. This honey-dew is often attractive 



THE INSECT WORLD. 



127 



to bees and wasps, who feed greedily upon it, and is yet more 
tempting to ants, whose relations to plant-lice merit more than a 
passing notice, since they are of decided economic importance. 

It is a common thing to see ants crawling over leaves infested 
by plant-lice, and it is often considered well that this should be 
so, under the erroneous impression that the ants feed upon plant- 
lice. In some cultivated fields ant-hills abound early in spring, 
the little mounds scarcely rising above the surface, being seen 
everywhere. We next find, shortly after, plant-lice infesting the 
roots or leaves of the growing crop. In truth, ants are protectors 
of plant-lice ; they are fond of their sweet excretion, and favor 
their increase and development in every possible way. The 
plant-lice seem to realize that they have nothing to fear, and 
readily yield to the ants of their sweets whenever approached for 
that purpose. Some species of aphids are indeed practically 
dependent upon ants for their existence. Where some of them 
lay their eggs we have not yet been able to learn, but perhaps 
they simply drop them to the ground, where their color and size 
render them invisible to our eyes. The ants find, gather, 'and 
carry them into their galleries, where they store them until spring. 
When vegetation starts and all conditions are favorable, the 
eggs are taken where they can hatch normally, the young lice 
being afterward carried to the plants upon which they are to feed. 
An instance nearly like this, save that the young are carried over 
winter, we find in the lice infesting corn roots, and undoubtedly 
there are many others. 

The study of plant-lice is difficult by reason of the matters 
already set out, and it sometimes requires years to supply a miss- 
ing hnk in their life history. The differences between them are 
not always well marked, and the tendency has been to recognize 
species as distinct when they feed on different food-plants. This 
basis has proved erroneous, however, and now the wonder is to 
find how many food-plants a single species may actually have. 

It has been mentioned that a number of plant-lice feed upon 
roots, and some species pass their entire life underground. Such 
are the RhizobiincB, which sometimes become distinctly injurious, 
as, for instance, when they occur on the roots of lettuce, in green- 
houses and out-doors. Sometimes they are found on the roots 
of trees or shrubs, quite usually attended by ants, which provide 



128 



A.V ECONOAIIC ENTOMOLOGY, 



for their distribution. As they never come to the surface, so far 
as we know, they are never winged, and are usually dull white 
in color, or with a slight tinge of green. The body is covered 
with a whitish powder and lacks honey-tubes. 

Fig. 94. 




Phylloxera vastatrix.—a. unaffected rootlet of grape; b, rootlets with newly-formed 
galls; c, same, with old and dried-up tissue; dd, groups of the lice on roots and root- 
lets ; e,f, female pupa, from above and below; g, h, winged females; i, an antenna; j, 
oviparous wingless female and her eggs ; k, root showing location of the eggs. 



An advance upon those root-living species is found in Phyl- 
loxera, which belongs with Chermes in a sub-family, Chermesma, 



THE INSECT WORLD. 



129 



distinguished by having only two discoidal veins on the fore- 
wings. The grape Phylloxera is known by reputation all over 
the world, and its ravages in European countries have called 
forth volumes of print. It has been thoroughly studied in our 
own country by Dr. C. V. Riley, among others, and from his 
works the following life history is taken. 

The insect winters on the roots of grape, mostly as a young 
wingless form. This starts growth in spring, rapidly increases 
in size, and soon commences to lay eggs, the young from which, 
like their mothers, remain wingless, are also sexless, and also lay 
eggs ; and so we may have a series of generations of similar 
creatures, no true sexes becoming developed, no wings appear- 
ing, and reproduction being entirely through unfertilized eggs. 
Sometimes, in midsummer, some individuals acquire wings, and 
thus we get migrating forms, which issue from the ground while 
yet in the pupa stage, and, as soon as they become winged, fly 
and spread to other vineyards in the vicinity. Eggs are then 
laid, usually on the under side of the leaves, from three to eight 
being the range, while five is perhaps the usual number. They 
are of two sizes, of which the larger produce females, the others 
males, and they come from the eggs fully developed and ready 
to reproduce. These curious creatures have become modified 
for the one purpose of reproducing their kind, and can neither 
feed, for the mouth is aborted, nor fly, for they have no wings. 
After copulation a single egg, almost as large as the insect itself, 
is developed in the female, and from it hatches a form which is 
like the type which started the cycle early in the season. Curi- 
ously enough, it occasionally happens that some of the wingless 
forms which remain underground also lay eggs of two diflerent 
sizes, producing males and females, and thus it appears that 
winged forms are not really necessary to the continuation of the 
species. Quite usually wingless individuals abandon the roots 
and crawl up the stems to the leaves, where they form the galls, 
which are the most prominent external mdications that a vine 
is infested. I have seen vineyards in New York and New Jersey 
in which almost every leaf showed these galls, yet withal no real 
injury had been done. In other words, most of the native 
American vines are able to sustain the attack of the species. 
This is not true of the vines in Europe, where this insect has 

9 



130 



AN ECONOMIC ENTOMOLOGY. 



been introduced, and, after a long series of experiments with 
insecticides, none of which proved satisfactory, resort was finally 
had to American stocks upon which the foreign varieties were 
grafted. This has proved effectual to an extent ; but it seems 
that, in the course of time, the period varying somewhat, even 

American stocks lose 
their exemption in 
Europe and become 
gradually subject to 
injury from the Phyl- 
loxera attacks. 

We have a number 
of species of this same 
genus infesting a great 
variety of plants not 
of economic interest. 
Perhaps the most com- 
mon is that which 
forms large, blister- 
like galls on hickory 
leaves, so prominent 
as to attract attention 
from even the most 
casual observer. If one of these galls be cut open, the inside 
will be found lined with numerous minute, yellow insects, with 
dusky wings which lie folded flat over the back, and in this par- 
ticular the Phylloxera differs from the typical aphids, which have 
the wings vertical when at rest. 

The subject of dealing with underground pests, or plant-Hce 
which feed upon roots, is one of importance, upon which the 
last word has not yet been said. As against the Phylloxera., 
bisulphide of carbon has proved useful, injected by means of a 
proper instrument into the ground at about the level of the roots 
and allowed to permeate the soil. The fumes are deadly to 
insects, and where they reach them in any but the egg stage, 
kill. The Phylloxera does not require attention in our country 
at the present time, and no large space need be given the subject 
of remedies against it. The matter is different when we consider 
the species which infest other cultivated plants ; whether Rhizo- 



FiG. 95. 




Galls of Phylloxera on grape-leaf. 



THE INSECT WORLD. 



bii7i2, or forms like the ' ' peach-louse' ' or the ' ' woolly apple- 
louse," where they may be on leaves, twigs, and roots at one or 
different times. Bisulphide of carbon can be used with good 
effect in such cases ; but it is rather an expensive application, and 
there is an element of danger that makes it desirable to employ 
something equally effective yet less liable to injure vegetation. 
Very satisfactory results have been obtained with tobacco, some 
under my own observations, some reported by other trained 
observers, and it seems fairly well proved that trenching around 
an infested tree, and filling into the trench a liberal supply of 
ground tobacco, refilling the trench immediately after, will have 
the effect of clearing the roots of these pests. This has been 
used more particularly against the peach aphids, and has been 
almost uniformly successful. Tobacco is a good fertilizer, and 
many dealers carry the coarsely ground product as part of their 
stock in trade. It is rather expensive as a fertilizer, but cheap as 
an insecticide, and a double value is obtained because besides 
killing the lice it also stimulates the trees or other plants. The 
use of tobacco, therefore, where root-lice are troublesome, is 
good farm practice. It may be well to say, however, that little 
or no benefit is derived from the use of stems spread upon the 
surface, or dug in, because there is not a sufficiently rapid extrac- 
tion of the nicotine, and this is, after all, the killing agent. The 
ground material on the other hand gives up its nicotine readily 
to a small quantity of moisture, and it will be quickly carried 
down and around the roots of the plants, into direct contact with 
the insects. In land infested by root-lice the use of commer- 
cial fertilizers is indicated. It has been found by experience that 
salty mixtures kill plant-lice more or less rapidly, and therefore, 
where root-lice are present, potash in the form of kainit and 
nitrogen in the form of nitrate of soda are advisable. I have 
frequently noticed that on land where these fertilizers are used 
underground insect life is scant, and direct experiments have 
proved that this condition of affairs is largely due to the salty 
fertilizers introduced into the soil. As against peach-lice in light 
soil, ten pounds of kainit to a five- or six-year-old tree of good 
size is about right, and the material should be spread on the 
surface evenly as far as the roots are likely to extend. 

In the more normal plant-lice the wings are better developed, 



132 



AN ECONOMIC ENTOMOLOGY. 



and we find differences in the form of the honey-tubes which are 
of generic or even sub-family value. Thus, we have some species 
of Pemphigus entirely without them, or with very small, mere 
tubercle-like structures. They live on a variety of trees, but 
perhaps more abundantly on poplar, and make galls, which are 
sometimes spherical and nearly half an inch in diameter. If we 
cut one of them after midsummer, we find it full of plant-lice, 



Fig. 96. 




Cock's-comb gall on elm, Colopha ulmicola.—a, elm-leaf showing galls; b, winter 
egg, covered by the skin of the true female; c, larva just hatched ; d, pupa; e, winged 
adult. 



the progeny of the single specimen which caused the growth of 
the gall early in the season. There are many other gall-producing 
lice, perhaps the best-known being the Colopha ulniicola, found on 
elm, and forming the "cock's-comb" gall. The popular name 
fairly describes the appearance of the abnormal growth, which 
is an inch or more in length and about one-quarter of that in 
height. None of these gall-making species are abundant enough 
to be seriously troublesome ; but quite the contrary is true of the 



THE INSECT WORLD. 



133 



Fig 




Woolly apple-louse, Schizoneura lanigera: show- 
ing a group of specimens on bark, a crevice on a 
branch, in which they congregate, and a winged 
form. 



"woolly plant-lice," belonging to the genus Schizoneura, These 
cover themselves with a secretion resembling fine cottony fibre, 
which conceals them more or less completely. Thus there may 
appear to be tufts of cot- 
ton attached to leaves 
or twigs, beneath each 
of which we find, how- 
ever, a great mass of 
plant lice busily en- 
gaged in feeding. The 
' ' alder - blight' ' and 
' ' beech-blight' ' are due 
to species of this kind, 
and more important 
than all is the ' ' apple- 
blight," or " the woolly 
apple-louse. ' ' This spe- 
cies, Schizoneura lani- 
gera^ has been intro- 
duced into other countries, and is known in England and Aus- 
tralia as the "American blight." Young trees are frequently 
injured by these aphids, which gather in masses on the trunks, 
and cause the death of the bark below the point of attack. The 
eggs may be found 

singly in the bark 9^- 
crevices during win- 
ter, completely envel- 
oped in the dry skin 
of the female, and 
from them appear, in 
spring, agamic, wing- 
less forms, which bear 
living young. This 
method of reproduc- 
tion continues until the 
winged type, which 
spreads to other localities, is produced in late summer. The 
sexed forms are wingless and mouthless, the female producing 
only a single egg ; but in the southern parts of our country it 




Schizoneura lanigera, root form. — a, galls caused by 



them on apple-roots ; b, 
winged form. 



wingless, wax-coated form ; c, 



134 



A AT ECONOMIC ENTOMOLOGY. 



is not unusual for the insects to survive winter in the adult con- 
dition, without producing a winter egg. One form of the species 
works deep underground on the fibrous roots ; and this is most 
difficult to deal with, and often causes the death of the attacked 
trees. When they appear on the trunk, treatment with either 
whale-oil soap or kerosene emulsion will be effective, and the 
underground form can be reached with bisulphide of carbon, or 
by a Hberal use of the tobacco or kainit, as recommended on a 
previous page. 

We have a number of species that attack our common orchard 
and farm crops, like the cherry-aphis, Myzus cerasi, the peach- 
louse, Aphis persicae-niger, the apple-louse. Aphis 77iali^ the 
hop-louse, wheat-louse, melon-louse, and others of equal reputa- 
tion. Almost every species requires different treatment, and it 
is difficult to lay down general rules. Cabbage-lice, which fre- 
quently do great injury, can be kept down by the prompt removal 
of all plant remnants left in the field after the heads are taken out 
and disposed of. On the stumps the insects continue to breed 
and live during the winter, if not disturbed, either as eggs or 
adults ; therefore, remove, use up, or destroy them as soon as 
may be. In pits where cabbage is kept to obtain seed the year 
following, a great number of lice pass the winter safely, but a free 
use of bisulphide of carbon will result in their destruction, so that 
the plants may be set without infestation in spring. An equally 
important point is keeping down all cruciferous weeds like mus- 
tard, shepherd' s-purse, and the like, because on these the insect 
flourishes as well as on cabbage ; therefore, clean culture, not 
only in the fields but along fences and roads, will pay over and 
over again. The corn-root louse can best be attacked through 
its guardian ant, which colonizes the helpless forms upon the 
roots in spring. Late fall-plowing the corn-fields is indicated 
here, that the nests of the ants may be destroyed at a season 
when they are unable to rebuild them. In those sections where 
fertilizers must be used, the kainit and nitrate of soda, already 
referred to, will prove. effectual. The ' * apple-louse' ' and ' ' cherry- 
louse," though different in appearance and habits, have a similar 
life history, and both pass the winter in the egg state, the eggs 
being laid on young twigs close to the buds. It is good policy 
to trim a tree on which there are many eggs pretty thoroughly in 



THE INSECT WORLD. 



winter, the cuttings, of course, to be promptly destroyed. Thus 
the number of individuals to start new infestation in spring 
will be greatly reduced. They breed agamically throughout the 
summer, and bring forth the sexed individuals late in fall or 
early in winter. I found them in New Jersey still ovipositing 
during the first week in December. Where pruning is not de- 
sirable, much can be done by spraying the trees, as soon as the 
eggs have hatched, with kerosene emulsion, — say, one part in 
t^velve or thirteen of water. Both of these species lay a number 
of eggs, but how many has not, I believe, been actually deter- 
mined. The species that infests hops has been already mentioned, 
and the best remedy against it is the total destruction of the vines 
immediately after the hops have been gathered, which will head 
off the production of the sexes. If this is delayed, spraying the 
plum-trees in fall or early in the spring before the hop-vines have 
made much start will be of great advantage. When the insects 
infest such plants as wheat, rye, or oats, it becomes difficult to 
adopt measures likely to be of much benefit. They multiply so 
rapidly, and the task of spraying a wheat-field is so enormous, 
that it is hardly worth while to recommend it. In such cases 
we must stimulate, to assist the plants in outgrowing injury, by 
applying such readily soluble fertilizers as nitrate of soda. This 
gives additional vigor to the plant, enabling it to sustain the 
attacks of the insect and mature a crop as well. Harvesting 
should not be delayed longer than absolutely necessary, unless it 
is observed that the enemies of the plant-lice are getting the bet- 
ter of them, and in that case nothing will be lost by leaving the 
grain as long as desirable. The aphid infesting cucumber- and 
melon-vines has been recently determined to be the same as one 
of those infesting oranges, and as that which frequently injures 
cotton. It has also been found on the strawberry, and seems, 
indeed, to be a very general feeder, passing the winter upon 
such wild plants as remain more or less green. Under favorable 
circumstances it increases rapidly in spring, and a migration 
starts to cultivated fields. Against this insect on melon-vines 
we can use bisulphide of carbon, covering the plants with a bowl 
or other covering, and evaporating a small quantity beneath it. 
This will kill the aphids in about an hour, and, though the pro- 
cess is slow, it has the advantage of being completely effective. 



136 



AN ECONOMIC ENTOMOLOGY. 



While, as has been stated, we cannot lay down general rules 
as to the treatment of all plant-lice, there are a few points that 
are always important. In the first place, the earlier the insects 
are dealt with, the more chance there is for the application to be 
effective. Plant-Hce should be treated just as soon as they are 
noticed ; the longer the delay the weaker the plants become, and 
the greater the thoroughness required to reach all the specimens. 

As a general insecticide, nothing is better than the kerosene 
emulsion, which, when diluted ten times with water, kills all the 
young forms and adults of the green species. It has been found 
by experiment that black or brown species are much more diffi- 
cult to destroy, and one part of emulsion in six or eight parts of 
water is more likely to be effective. Fish-oil soap is effective at 
the rate of one pound in six gallons of water ; or, as against the 
brown species, one pound in four gallons of water. Thorough- 
ness of application is always essential. It must be remembered 
that these poisons act by clogging the spiracles, or by entering 
into the body through them. Unless the application is thorough, 
the insects may be weakened but not killed, or, if rendered help- 
less for a time, they may recover, and a second dosing becomes 
necessary where one, more thoroughly applied, would have been 
sufficient. Where it is not advisable to apply either of the ma- 
terials mentioned, we can use tobacco with good prospects of 
success, either as a decoction or a very finely ground powder. 
In greenhouses, tobacco is a standard remedy, and its frequent 
application results in keeping them moderately free from these 
pests. It may be applied as already described, but is more usu- 
ally burnt to make a smoke, which is poisonous to the insects. 
A milder method is to keep the steam-pipes covered with moist 
stems, so as to produce a nicotine-laden atmosphere. Very often 
plant-lice appear in forcing-beds, and these we can generally 
destroy with bisulphide of carbon placed in a shallow dish and 
left in the covered beds overnight. Greenhouse benches may 
be rid of the pests in the same way, covering the plants for two 
or three hours with a frame or box, and evaporating a small 
quantity of the bisulphide. A fumigating-box made of wood, 
canvas, tin, or other material, large enough to contain potted 
plants of good size, should be in every greenhouse and nursery. 
A number of pots of infested plants may be placed in such a box, 



THE INSECT WORLD. 



the door closed, and bisulphide evaporated from a vessel hung up 
just below the top of the box. As the vapors descend, they will 
kill the insects infesting the plants, which may then be sent out 
free from all insect troubles. One dram of liquid per cubic foot 
of space will be about the right quantity not likely to hurt vege- 
tation, while killing all lice by the time the liquid has entirely 
evaporated. 

The "jumping plant-lice" are so called from their habit of 
leaping readily, though, as a matter of fact, their resemblance is 
rather to the tree-hoppers, and most of all they recall a miniature 



Fig. 99, 




The pear-psylla.— a, pupa from under side, showing the thread-like piercing lancets; 
to the right, a winged adult and stalked egg. 

cicada. They all belong to the family PsyllidcB, some species of 
which are exceedingly troublesome, — e.g., the "pear-psylla," 
Psylla pyricola. This infests pear-trees in the more northern 
parts of the country, extending south to Maryland, though 
south of New York State it occurs in isolated patches only. It 
does its injury, first, by sucking the juices of the plant and so 
weakening it ; second, it exudes honey-dew in such quantity as 
actually to close the pores of the leaves and young bark, over 
which a fungus forms and checks growth. It commonly attacks 
the stalk of the fruit, or the twig just where it is fastened, and 
the result is nearly always a cessation of growth in the pear itself. 
The species has several broods during the season, but winters as 



138 AN ECONOMIC ENTOMOLOGY. 

an adult in any available shelter, — under loose bark of trees, under 
rubbish, and, in fact, wherever there is an opportunity to hide. 
The application of whale-oil soap early in spring, just as the buds 
begin to swell, will generally kill the insects, which are then ready 
to emerge from winter quarters. Good practice is to scrape all 
the loose bark from the trees during the winter, and burn it ; 
wash at that time with a potash or strong kerosene mixture, and 
in spring use the whale-oil soap at the rate of one pound in one 
gallon of water, being careful to confine the spraying to the 
trunk and larger branches. If this is thoroughly done, it forms 
a film over the trunk which no insect will voluntarily pierce. A 
liberal application of whitewash is also advantageous, and should 
be put on with a knapsack sprayer and Vermorel nozzle. 

We have many species belonging to this family, some of them 
gall-makers on the hackberry, or Celtis ; but none others occur in 
sufficient numbers to be of economic importance. 

The "leaf-hoppers" belong to the {■a.mAy Membracidcs, and 
contain many odd-looking types. The general shape has been 
compared to a beech-nut, and the most prominent part is always 
the thorax, which may be produced into a curved horn forward, 
into a broad hump, into a pair of curved lateral horns, into a 
double hump, or into a dozen other forms. The species occur 
on trees, shrubs, vines, and indeed on vegetation generally, 
though rarely in great numbers. Some species excrete honey- 
dew, some lay their eggs in white frothy masses on plants, and a 
few are attended by ants, thus resembling the plant-lice. Only 
a few are troublesome, and of these are the "buffalo tree- 
hoppers," belonging to the genus Ceresa. They derive their 
common name from the fact that the thorax is cut off square 
anteriorly, and projects into two short, lateral, curved horns, 
which give it a fanciful resemblance to the massive front of a 
buffalo. The head is small and scarcely noticeable, the horns 
not being recognized at first as really belonging to the thorax. 
This insect causes injury by laying its eggs in slits on twigs of 
apple- and other fruit-trees. There appears to be almost a poi- 
soning of the plant tissue, because the wounds, though apparently 
slight, do not readily heal over, but rather open up the year 
following, giving rise to an abnormal swelling, weak and morbid 
in character, unable to sustain the weight of any fruit that occurs 



THE INSECT WORLD. 139 

beyond it, and ready to break in the first high wind. On old or 
large trees the insects are rarely dangerous, because their injury 
results in only a little pruning, but on young trees they may 
cause deformities ; hence, if the insects are noticed in a young 
orchard, it will be advisable to go over it carefully during the 
winter, to trim out all infested twigs or branches, burning the 



Fig. too. 




Buffalo tree-hopper, Ceresa bubalus.—a, adult; 5, c, d, tarsus, antenna, and wing- f,g, 
tip of abdomen, showing ovipositor. 

cuttings to destroy the eggs. Active insecticide applications are 
hardly indicated. 

Next come the cicadas, or "harvest-flies," often miscalled 
locusts, and the largest of the Homoptera. They are easily known 
by their broad, transparent wings, the large head with prominent 
eyes set on each side, and by their intensely shrill, loud song, 
which during midsummer forms one of the common sounds 
of the country. The author of this concert is the ' * dog-day 
harvest-fly," greenish in color, more or less marked with black. 
The noise is produced by an elaborate drumming and resonating 
structure on the under side of the thorax and abdomen of the 



140 A A' ECONOMIC ENTOMOLOGY. 

males, who alone are musical, giving rise to that oft-quoted old 
saying, — 

"Happy the cicadas' lives, 
For all have voiceless wives." 

The plan of the sound-organs can best be described bv com- 
paring to a slightly convex-bottomed tin pan, which makes a 



Fig. ioi. 




a, Ceresa bubalus, ovipositing in slits b ; the The dog-day harvest-fly, 

eggs, if, arranged as at c ; old, scarred punc- Cicada tibiceji. 

tures shown at e. 

snapping noise whenever the bottom is forced to change from 
convex inwardly to convex outwardly. By an exceedingly rapid 
snapping of the convex "drum" of the cicada, the continuous 
shrilling sound is produced, intensified and modified by the vari- 
ous tense membranes more or less surrounding it. 

The most famous species of this family is the "'periodical 
cicada," or " seventeen-year locust, " Cicada septe7idecim. It is 
of especial interest from the unusually long larval period, re- 
maining in the Middle and Northern States sixteen years beneath 



THE INSECT WORLD. 



141 



the surface of the ground, feeding- on the juices of roots, and 
transforming in the spring of the seventeenth year into a winged 
adult. No less than twenty-two broods have been tabulated in 
the United States, chiefly through the efforts of the late Dr. C. 
V. Riley, so that we know approximately how each is distributed, 
and are able to foretell with certainty when the insects will appear 
and about what territory they will cover. A further point of 



Fig. 103. 




The periodical cicada, C. septendecim.—a, pupa, ready to change ; b, pupa-skin from 
which the adult c has emerged ; <f , eggs, taken from the egg-punctures d. 

interest is that in the more southern States the period of develop- 
ment is somewhat shorter, thirteen years only being required to 
bring the insect to maturity. Much confusion was caused in 
arranging the broods until this fact was understood ; but experi- 
ments have now been made in transferring eggs of the thirteen - 
year variety to northern regions, and eggs of the seventeen-year 
variety to southern regions ; the object being to ascertain whether 
climate would affect the larval period in the first generation. 
These experimerrts have not yet terminated. This cicada makes 
up for the long intervals at which it occurs by the enormous 
numbers in which it appears, and in a "locust" year its loud 



142 



AA^ ECONOMIC ENTOMOLOGY. 



Fig. 104. 



song may be heard at all periods of the day and until late into 
the night, from the end of May to nearly the end of June, louder 
and more intense on warm or hot days. No injury is done by 
the insects in feeding, but their egg-laying habits often cause 

considerable trouble. Though 
the larvs feed under ground, the 
eggs are laid in the twigs and 
branches of trees ; a series of slits 
being cut by the powerful ovi- 
positor of the female, forming 
smooth chambers in w^hich the 
eggs are arranged in series. 
There is nothing to be done when 
such a brood occurs except take 
the injury and make the best of 
it. Of course valuable plants or 
trees can be protected by mos- 
quito-netting, but my statement 
applies to ordinary farm and or- 
chard crops. The fact that we 
know when the insects are to 
appear makes it possible for the 
fruit-grower to guard himself to 
some extent by not setting out 
voun^ stock. On old trees no 
serious injury will be done, and 
if no pruning is attempted during 
the winter preceding, the insects 
will probably find an abundance 
of useless twigs to oviposit in. 
Young trees, however, are some- 
times so injured as to make them 
practically useless, either by com- 
pletely spoiling the shape, or by 
so weakening the main branches 
that they never become strong enough to bear a proper top. 
Wherever the English sparrow has been introduced, the period- 
ical cicada is doomed. These birds seem to have an intense 
hatred for the insects, attacking and pulling them to pieces in 




6 



a: 

Cicada egg-punctures : at a, freshly 
made ; at 3, old and distended. 



THE INSECT WORLD. 



143 



the most wanton manner. Near the large cities where the spar- 
rows are numerous, entire broods have already been destroyed. 
In 1889 the insects appeared in large numbers in Prospect Park, 
Brooklyn, and in the surrounding woodland, but in an entire 
day's careful search I found only a single branch containing 
eggs ! 

That it may be known in a general way where and when these 
insects may be expected, the following record of the broods is 



Fig. 105. 




Cicada egg-punctures, seen at a, from outside; b, cut down on puncture to show the 
two chambers ; c, side view of an egg-chamber ; rf, a pair of egg-chambers from which 
the eggs have been removed. 

given, with the date of last appearance, the time when they may 
be next expected, and the country covered by them. The state- 
ment is made up from the reports and bulletins of the United 
States Department of Agriculture. 

Brood I. last appeared in 1893 ; will appear again in 1910. 
Occurs in Massachusetts and Connecticut in small numbers. 

Brood II. appeared last in 1895 ; will appear again in 1908. 
It covers the northwestern part of Georgia, and appears at thir- 
teen-year intervals. No very definite limits have been assigned 
to it. 

Brood III., originally supposed to occur in Ohio in 1887, was 
based on erroneous information. 

Brood IV. is of the thirteen-year variety, appeared last in 
1883, ^"^^ will appear again in 1896, covering parts of Florida, 



144 



AjV economic entomology. 



Alabama, Mississippi, and Tennessee, but it seems not to be 
very numerous. 

Brood V. occurred last in 1888 and will appear next in 1905. 
It covers parts of Southern Wisconsin, Northern Illinois, the 
eastern third of Iowa, the northwest counties of Indiana, and the 
more southern part of Michigan. This brood is very numerous 
in individuals. 

Brood VI. occurred last in 1884 and will occur again in 1897, 
being of the thirteen-year race. It occurs in the southwestern 
part of Mississippi and extends into Louisiana, infesting a com- 
paratively small territory only. 

Brood VII. occurred last in 1885, and will occur again in 
1898, being also of the thirteen-year race. It occurs in South- 
ern Illinois, Kansas, Missouri, Georgia, Louisiana, Arkansas, 
Mississippi, and Tennessee. 

Brood VIII. appeared last in 1889, and will appear again in 
1906. It covers a portion of Southern Massachusetts, a large 
part of Long Island, extends along the Atlantic Coast to the 
Chesapeake Bay and for some distance into Pennsylvania, Ken- 
tucky, West Virginia, Ohio, Indiana, and lUinois 

Brood IX. occurred last in 1891 and will appear again in 1908. 
It occurs in parts of Nebraska and probably in portions of Colo- 
rado, though it has not yet been satisfactorily limited. 

Brood X. occurred last in 1888 and will appear again in 1901, 
being of the thirteen-year race. It has been recorded from Texas, 
but is yet a doubtful brood, requiring fuller observations than 
have been made to substantiate it positively. 

Brood XI. occurred in 1893 ^^^^ will occur again in 1910. It 
is a large one, covering parts of North Carolina, Virginia, Mary- 
land, Illinois, and Indiana, although not the entire State in any 
instance. 

Brood XII. occurred last in 1894 and will make its next ap- 
pearance in 191 1. It extends along both sides of the Hudson 
for its full length, into Southern New York, Connecticut, through 
the entire State of New Jersey, and into Pennsylvania, Ohio, 
Michigan, North Carolina, Virginia, Maryland, and Delaware. 

Brood XIII. appeared in 1895 and wdll appear again in 1912. 
It occurs throughout a large part of Iowa, and probably a portion 
of Ilhnois and Missouri. 



THE INSECT WORLD. 



145 



Brood XIV. will appear in 1896, and covers Western Missouri, 
extending into Kansas, Arkansas, Iowa, Northern Texas, and 
Indian Territory. 

Brood XV. will occur in 1897 Western Pennsylvania and 
Ohio, extending into Kentucky and West Virginia. 

Brood XVI. appeared last in 1893 will appear again in 
1906, being of the thirteen-year race. It occurs in the northern 
portion of Georgia, but its limits are not well defined. 

Brood XVII. will appear next in 1898 and at intervals of 
seventeen years thereafter. It occurs in Wisconsin, the north- 
ern part of Ohio, Pennsylvania, and parts of New York, as well 
as isolated localities in New Jersey. The brood is a small one, 
however, especially in the southern part of its range, and appar- 
ently dying out. 

Brood XVIII. occurred in 1894 and will occur again in 1907, 
being of the thirteen-year race. It is a very well-recorded one, 
and covers Southern Illinois, nearly all of Missouri, Louisiana, 
Arkansas, Indian Territory, Kentucky, Tennessee, Mississippi, 
Alabama, Georgia, North and South Carolina. 

Brood XIX. occurred last in 1882 and will occur again in 

1899. It is a small one and confined to a few counties in Central 
and Northern New York, — that is, Monroe, Livingston, Madi- 
son, Yates, and, perhaps, those immediately adjoining. 

Brood XX. appeared last in 1883 and will appear again in 

1900. It occurs in Western New York and Pennsylvania and 
Eastern Ohio. It is a small brood and does not attract attention. 

Brood XXI. occurred last in 1884 and will occur again in 

1 901. It covers parts of North Carolina, Virginia, and West 
Virginia, and may possibly occur in Massachusetts (Martha's 
Vineyard) as well. 

Brood XXII. appeared last in 1885 and will appear again in 

1902. It occurs on Long Island, in New York, New Jersey, 
Pennsylvania, Delaware, Maryland, District of Columbia, Vir- 
ginia, West Virginia, North Carolina, Tennessee, Georgia, Ohio, 
Kentucky, Indiana, Illinois, Michigan, and Wisconsin. Brood 
VII. , of the thirteen-year race, and Brood XXII. , of the seventeen- 

,( year race, come in contact in Southern Illinois and Northern 
] Georgia, and it may happen, as it did in 1885, t^iat these two 
broods appear during the same year at the same place. 

10 



146 



AN ECONOMIC ENTOMOLOGY. 



The FiilgoridcE, or "lantern-flies," contain some very remark- 
able and striking species in tropical countries, but are sparsely 

represented by somewhat rare 
species in our fauna. Perhaps 
the most common of our forms 
are species of Onneiiis, pale 
green or whitish, having some- 
what the appearance of small 
wedges, the broad wing-covers 
being flattened vertically. They 
may be found on the under side 
of leaves of various plants, par- 
ticularly grape, sucking the 
juices, preferably from the larger 
veins or ribs. None of them are 
mentioned only that our common 




Fulgoridce, 
sulcipes ; b. 



or lantern-flies.— a, Scolops 
Pceciloptera truncaticornis ; 



twice natural size. 



of the family Cer- 



FlG 



injurious, and the family is 
species may be recognized. 

The "spittle-insects," or "frog-hoppers, 
copidcB, resemble some forms of tree-hoppers in their habit of 

laying the eggs in little, 
frothy, white masses. These 
masses of ' * frog-spittle' ' are 
often noticed in grass lands, 
but their true character is 
rarely understood. Unlike 
the "tree-hoppers," the 
CercopidcB never have horn- 
like processes or projections, 
but are usually squat, some- 
what angular, yet flattened 
creatures, whose popular 
name, "frog-hoppers," has 
been obtained by the some- 
what fanciful resemblance of the insects to a frog when just ready 
to leap. Few of these species, so far as I have any information, 
are sufliciently injurious to be of economic importance. They 
feed on a great variety of plants, but are rarely common on culti- 
vated crops, 

It is different with the ' ' leaf-hoppers, ' ' or Jassidce, which are 




^4 

larva, en- 
larged; 5, same, natural size, on a leaf bearing 
"frog-spittle;" c, the adult, enlarged. 



Cercopid, or spittle-insect. 



THE INSECT WORLD. 



147 



small, slender insects with the wing-covers narrow and slightly- 
thicker than the broad hind wings, which are the only effective 
organs of flight. The thorax is broad and square, the head 
usually short and very broad, in most cases somewhat crescent- 
shaped, with prominent eyes occupying a large part of the sides. 
If we examine the insects on the under side it appears as if the 
beak or rostrum came out from the breast between the front legs, 
so much is the head curved under. The antennae are very short 
and bristle-like ; the legs are well developed, the hind pair espe- 
cially being very long and powerful, set with spines on the tibiae, 



Fig. 108. 




Development of a Jassid, Agallia sangidtwlenta.—a, larva-, b, pupa ; c, adult ; also head 
of same from below. 



somewhat as in the grasshoppers, and like them the insects are 
powerful leapers. This they are in all stages, but as adults they 
are also ready fliers, and hence difhcult to capture. Many of 
them are common and, feeding on cultivated plants, are injurious. 
As in other families, there is considerable difference in the life 
history of the species ; but of most of those of economic impor- 
tance it may be said that they pass the winter in the adult stage, 
hiding in all sorts of rubbish or in crevices, wherever they find 
opportunity. Some time in spring they leave their winter quar- 
ters, attack the plants upon which they feed, and lay eggs. The 
number of hibernating individuals is usually not very great, but 
they lay a large number of eggs, and the young and future broods 
become troublesome. One of the best-known species is that 



148 



A.¥ ECONOMIC ENTOMOLOGY. 



found on grape-vines, which causes the leaves during the latter 
part of the summer to become marked with brown spots, some- 
times in such numbers that they become confluent and the entire 
leaf is ' ' burnt. ' ' If we tap a leaf at this time swarms of little 
creatures, not exceeding an eighth of an inch in length, prettily 



marking. Many are the crops infested by these little hoppers, 
and, though there are good characters by which they can be 
distinguished scientifically, yet to ordinary observation they 
appear much aHke, except in size and color. 

The methods of preventing injury are much the same for all 
species. In the first place, where experience has shown that the 
insects are likely to occur during the summer, all rubbish should 
be disposed of in the course of the winter preceding. This can 
be done by collecting and burning, or by plowing under very 
early and cultivating so as to leave a clean field. Loose bark, 
dead branches, twigs, or scaly fence-posts should all be attended 
to, and piles of dead grass or weeds along fences or in corners 
should be burnt or otherwise destroyed. In this way much can 
be done to prevent the insects from getting a start. When the 
larvae are first noticed great success has been attained in vine- 
yards by walking along the sides of vines strung on wires, dis- 
turbing them to start the insects, which jump wildly and readily. 
A shingle or palm- leaf fan smeared on both sides with coal-tar or 
insect-lime should be kept in constant motion near the vines, and 
by this fanning a great quantity of the jumping larvae will be drawn 
to the smeared surfaces and destroyed. This method is practical, 
and has been found effective within my own experience ; so large 
a proportion of the insects being captured in the course of two 



The grape-Ieaf-hopper, Erythroneura vitis ; at rest, 
and with wings expanded. 




Fig. 109. 



marked with green, rosy- 
red, and yellow, will fly 
or jump from them. 
EarHer in the season 
they are yellow or green- 
ish, without wings, but 
jump readily if disturbed. 
On roses we find a simi- 
lar appearance, and here 
the species are green or 
yellowish, without much 



THE INSECT WORLD. 



149 



days that subsequently they were not noticeable. If this method 
cannot for any reason be used, the kerosene emulsion diluted ten 
times may be appHed, and the vines should be disturbed as the 
spraying is done. If a Vermorel nozzle is used, it can be held 
a little distance from the vines and will hit the insects while they 
are in the air, either jumping or flying. The wetting done in 
this way is as effective as when done on the leaves, and there is 
even more chance of hitting them in the air than at rest. So the 
effort should be to fill the air around the vines, for some little 
distance, with the fine mist-like spray so easily produced by the 
Vermorel nozzle. This method should also be made use of if the 
insects are found in numbers after they are winged. It is appli- 
cable in many cases, but hardly practical where insects feeding 
upon wheat or similar plants are to be dealt with. It has been 
found that the adults are attracted to light, and the electric arc- 
light, particularly, destroys myriads of them. I have seen in a 
single globe no less than one pint of leaf-hoppers, and the num- 
ber included in that measure is almost impossible of estimate. 
The unfortunate feature in this method is that the damage to 
vegetation has been done when it takes effect, and it is in the 
line of preventing injury during the year ensuing, which can 
be accomplished as readily by the winter treatment. In fact, 
cleaning up during winter is strongly insisted upon, and will pay 
many times over. A great number of leaf-hoppers are found in 
grass lands, where they do much more injury than is generally 
supposed, — an experiment in Iowa seeming to prove that just 
about one-half the crop is destroyed in badly infested fields. The 
experiment was made by setting off two patches of equal size, as 
nearly equal in all respects as could be made, leaving the one 
untreated and collecting the leaf-hoppers from the other. Cattle 
were pastured on both parcels, and that on which the insects 
were collected supported just double the number. The insects 
were collected by means of shallow pans coated with tar, drawn 
by man or horse-power, and in jumping or flying up before it they 
alighted immediately behind the edge, upon the tar. It requires 
very few such collections to practically exterminate the pests on 
a tract of land, but of course the question remains whether it 
will pay. On grass lands winter treatment is hardly practicable, 
and collecting in pans is perhaps the only available method. 



AN ECONOMIC ENTOMOLOGY. 



Fig. iio. 




A water-boatman, Notonecta species. 



Fig. III. 



The sub-order Heteroptera contains those species of bugs in 
which the upper wings are thickened toward the base and the 

terminal portion is membraneous 
and veined. We have a large 
number of species belonging here, 
and some large series may be en- 
tirely left out of consideration. 
Such, for instance, are the 
aquatic families, all of which seem 
to be carnivorous in habit, 
whether they live on the surface 
of the water or beneath it. One 
of the water-boatmen, a species of Corisa, may be mentioned, 
because its eggs are used as food in Mexico. These eggs are 
nearly white in color, about one-tenth of an inch in diameter, and 
laid in great numbers on sedges, where they are collected by the 

natives. Judging from the usual odor 
of the bugs and from the taste of 
such eggs as are sometimes involun- 
tarily eaten on fruits, it requires a 
specially-developed gustatory appa- 
ratus to enjoy a meal of this char- 
acter. This suggests the fact that 
one of the peculiarities of this sub- 
order is the more or less marked 
presence of odors, differing some- 
what in kind, but all of them intensely 
disagreeable. In bed-bugs we have 
one type in marked perfection, while 
in the ' ' squash-bug' ' we find an ex- 
cellent illustration of another. 

One of the water-bugs that some- 
times attracts attention is a huee 
creature, two 
length, broad 
gray in color, 
a short beak 




or 



Belostoma americana. 



three inches in 
in proportion, livid 
flattened above, with 
and very large, thick- 



ened forelegs, often drawn in considerable numbers to electric 
lights. It is the Bdostoma americana^ which lives in ponds and 



THE IXSECT WORLD. 



Streams, where it feeds on other insects and small fish, destroy- 
ing large numbers. During the night the winged individuals 
leave the ponds, pair, and fly to new localities to lay their eggs. 
So abundantly do they occur that they sometimes become nui- 
sances near electric lights, and have been termed from this fact 
' ' electric-light bugs. ' ' 

Sometimes we find slender, spider-like creatures of a brown 
color scudding over the surface of the water at a rapid rate, and 



Fig. 112. 




A water-strider, Rheumatobates rileyi, female. — a, anterior tarsus ; b, ovipositor ; c, hind 

tarsus. 

these are "water striders," or HydrobatidcB. They are inter- 
esting because some of them pass their entire lives upon the 
ocean, m.iles from land. These are said to feed upon the juices 
of such dead fish and other animals as they find on the surface, 
and probably also on the floating masses of sea-weed occurring 
in equatorial regions where they are most common. 

The first family of economic importance among the terrestrial 
species is the Reduviidce, containing species of quite large size, 



AN ECONOMIC ENTOMOLOGY. 



Fig. 113. 




Wing of Heteropteron with all the regions 
named. 



distinguished by a comparatively small, narrow head with promi- 
nent eyes, and by a short, very stout, curved, pointed beak, 
which rests, when not in use, in a little groove between the 
front legs. The insects are strongly built, with legs usually well 
developed, and, as they are predaceous, are to be regarded as 

friends. The very small 
head and short, slightly 
curved, pointed beak, serve 
to distinguish them from 
the plant-feeding species. 
They readily puncture the 
skin of any one handling 
them carelessly, and the 
' ' bite' ' is exceedingly pain- 
ful, the poison injected 
into the wound being intensely irritating, and sometimes causing 
considerable sweUing, with pain lasting for days. One of the 
species has adapted itself to life in houses, feeding upon flies and 
bed-bugs. The young have the curious habit of coating them- 
selves with particles of dust or fibre which conceals them perfectly 
from casual observation. A similar species, Conorhimis sangui- 
sugis, nearly an inch in length, is found in houses in the South- 
ern States, — not to feed on bed-bugs, however, but as a bed-bug 
itself. It is especially inclined to bite children, and many cases 
of supposed spider-bites are believed by Dr. Leconte to be really 
due to this insect. He also states that he has known a patient 
to suffer from the effects of such a ' ' bug' ' bite for nearly a year. 
Fortunately, the insects are not very common, their large size 
and black color, with red markings, making them easily visible 
and readily destroyable. 

The largest species occurring in the Eastern United States is 
the so-called "wheel-bug," Prionidus cristatus, and this becomes 
more common southwardly. It lays its curious, jug-like eggs in 
hexagonal masses on bark of trees, fences, or any other conven- 
ient locality, and the adult, which is brown in color, is one of the 
most readily recognized of our species. The thorax has a semi- 
circular crest, the edge of which is toothed, so that, viewed from 
the side, it has somewhat the appearance of a segment of a cir- 
cular saw. It attacks all sorts of insects, piercing them with its 



THE INSECT WORLD. 



153 



powerful beak and sucking their juices. There are other species 
of the same general appearance common everywhere, and some 
even maintain themselves in our cities, feeding upon the larvae 
injuring shade-trees. I have noticed certain of them in New 
Brunswick destroying the larvae of the elm-leaf beetle in large 



Fig. 114. 




The wheel-bug, Prionidus cristatus, in all its stages; natural size. 



numbers. Taking it altogether, we find in this family mainly 
forms that are beneficial to the farmer. 

There are a few other common species, also predaceous m 
character, but much smaller and more slender than the pre- 
ceding, belonging to the family Nabidce, Our common species 
of the genera Nabis and Coriscus are yellowish in color, flat- 
tened above and rather roughened, with long legs, but other- 
wise resembhng in head and beak the usual predaceous form, 
except that the beak is longer and more slender. They are 
found on flowers and leaves, preying upon almost anything that 
they can conquer. 



154 



AN ECONOMIC ENTOMOLOGY. 



A very curious, chunky little species, with the sides of the 
abdomen much elevated, and the forelegs much broadened and 
fitted for clasping, belongs to the genus Phyviata and the family 
Phymatidtz. It is yellow and brown in color, and has the habit 

of placing itself in the centre of 
FiG- 115- certain flowers, in such a manner 

as to seem a part of the flower 
Itself It is thus in position to seize 
any unlucky insect that comes 
within reach, and, although it is 
scarcely a quarter of an inch in 

Fig. ii6. 





Nabis fusca. 



Phymata erosa.—a, b, adult, from above and 
side; c, front les: d. beak. 



length, it is sufficiently powerful to hold and conquer even 
honey-bees. Butterflies are frequently its victims, and it is one 
of the oddest forms in this order. 

We sometimes find on the under side of leaves of tree and 
shrub, little whitish, flat creatures, with gauze-like, broad wing- 
covers, and a broad, gauze-like expansion covering the thorax. 
These belong to the family TiugitidiF and are among the prettiest 
species in the order. There is no difficulty in recognizing them 
in the adult stage, by their lace-like or reticulated covering, 
which is sometimes banded with brown or spotted. Beneath 
this covering the insects are black or brown, and occasionally 
they increase sufficiently to do some injury to the plants upon 
which they feed. The adults usually live through the winter and 
lay their eggs in spring ; but sometimes eggs are laid in fall, and 
the insects winter in that stage. For shelter, fallen leaves are 
usually employed, or the adults creep under loose bark scales or 
into crevices, and we must agam recommend winter work in clear- 



THE INSECT WORLD. 



155 



ing up rubbish of all kinds, or plowing it under. Where this is 
done there will be no necessity for active treatment in summer. 
They may be destroyed at that time, however, by the application 
of the kerosene emulsion diluted ten times, or by the whale-oil 
soap used at the rate of one pound in four gallons of water. 

Perhaps no insect is better known than the " bed-bug," Acan- 
thia lectularia, which occurs, especially m hotels, throughout the 
country. It is wingless, very much flattened, broadly oval in 
shape, and red brown in color. It is 
able to crawl into the narrowest crev- Fig. 117. 

ices, and no bedstead has yet been 
made which does not afford it shelter. 
It is nocturnal in habit, seeking its 
prey at night and occasionally making 
life miserable. Where a house be- 
comes thoroughly infested, specimens 
are found under baseboards, beneath 
loose paper, in cracks in the plaster, 
and in fact wherever there is an open- 
ing large enough to insert the blade 
of a thm knife. They multiply rapidly 

and are able to do without food for a The bed-bug, Acanthxa lechdarta- 

considerable period. In houses that 

have been long abandoned, bed-bugs of all sizes may sometimes 
be found, perfectly transparent as if they had been always with- 
out food. It is probable, therefore, that they are able to subsist 
upon some substance other than human blood. Where they are 
accidentally introduced into a house and confined to beds, there 
is nothing better for use than kerosene or gasoline. It should be 
liberally applied in joints, crevices, and wherever there is the 
least opening, so as to reach the bottom before the material soaks 
into the wood. A single thorough application of this kind 
usually proves successful, although it would be better to renew it 
a week afterward, to reach forms that have hatched from eggs 
since the previous application : for m my experience neither 
kerosene nor gasoline destroys the eggs with certainty. Another 
effective remedy is corrosive sublimate dissolved in alcohol, and 
this has the advantage of being more lasting, remaining effective 
for some time after it is applied. It is, however, exceedingly 




AN ECONOMIC ENTOMOLOGY, 



poisonous, and must be used with that fact in mind. Professor 
Comstock states that where, in travelHng, ' * one is forced to lodge 
at places infested by these insects, or by fleas, protection from 
them can be had by sprinkling a small quantity of pyrethrum 
powder between the sheets of the bed on retiring. ' ' 

Rather closely allied to the bed-bug in structure, if not in habit, 
are a number of very small, flat species, with fully developed 
wing-covers, which are usually found on flowers, feeding upon yet 
smaller insects and perhaps also on eggs. They belong to the 
family A?ithocoridt^, and the most common is a minute black in- 
sect with yellow-tipped wings, known as 
the "insidious flower-bug," Triphleps in- 
sidiosus, credited with feeding among others 
upon the insects in Phylloxera galls. 

Now follow the CapsidiB, containing a 
long series of species softer in texture than 
most of those heretofore described. They 
are plant bugs par excellence, found on 
vegetation of all kinds, frequently in very 
great numbers, and feeding upon their 
juices. The wing- covers are soft and flex- 
. . . ible throughout, though thickened basally. 

Triphleps mstdiosus, the o 7 o ^ j 

" insidious flower-bug." They puucturc leaf, twig, stem, or flower, 
and, where these punctures have been 
made, there is usually a drying of the tissue which interrupts the 
nourishment of the plant and often causes injury. As a rule, the 
species are green or yellowish in color, sometimes black speckled, 
and occasionally with reddish markings. In form they vary, 
being sometimes broadly oval, sometimes quite narrow. The 
antennae are usually long and prominent, and the ' * buggy' ' odor 
is well developed. We have a number of species abundant 
enough to be injurious, and the question of dealing with them is 
sometimes complicated. The insects winter in different stages ; 
often as an egg laid in twigs, as with the " four-lined plant-bug," 
Pcecilocapsus lineatus, attacking among others currant and goose- 
berry bushes. The application of insecticides to kill plant-bugs 
has been found unsatisfactory. They resist even the kerosene 
emulsion quite strongly, and in order to kill adults it cannot be 
diluted more than five times. Even against immature forms a 




THE INSECT WORLD. 



157 



very strong mixture is necessary, and not more than six or seven 
parts of water can be added if a good effect is expected. In the 
case of the four-Hned bug already mentioned, the knowledge 
that it lays its eggs near the tips of currant and other twigs 
suggests a careful winter pruning, the cut twigs and branches to 
be burnt, and in this way injury may be prevented during the 
year following. This measure is successfully used where shrubby 



Fig. 119. 




Pcecilocapsus lineatiis, four-lined plant-bug, natural size and enlarged : also egg mass 
in currant, and, at e, a single egg, greatly enlarged. 

or woody plants are attacked ; but on succulent annuals, collect- 
ing the insects in the morning, before they have become active, 
by shaking them into some sort of receptacle, is the most satis- 
factory method. 

In the Cotton belt there was no more troublesome insect, some 
years ago, than the red-bug," or cotton-stainer," Dysderciis 
suturelhis, so named from the fact that its excrement, voided in 
the opening bolls, stained the cotton red, and thus caused it to 
become of inferior value. Since cotton-seed has become almost 
as valuable as the cotton itself, and is now completely used up, 
it has been found that these insects have become practically harm- 
less. It seems that they were enabled to multiply unduly in the 
heaps of decaying cotton-seed, and since at present no such heaps 
exist they cannot increase so rapidly. They also attack oranges 
in Florida, and Professor Comstock recommends that they be 



A A' ECONOMIC ENTOMOLOGY. 



trapped by placing small heaps of cotton-seed in the groves, to 
attract them where they can be easily destroyed with pure kero- 
sene. 

Fig. I20. 




Dysdercus siiturellus. — a, pupa; b, adult. 

In the family LygceidcB we have species that are oblong in 
shape, rounded behind and flattened above. They have quite 

long beaks, a moderate- 
sized head, and all of 
them are vegetable feed- 
ers. The body is rather 
hard, and the insects are 
often brilliantly or gaudily 
colored, black and red, 
in the strongest possible 
contrast, being favorite 
combinations. Some be- 
come nearly an inch in 
length, though most of 
them are much smaller. 
The best known of the species is the "chinch-bug," Blissus 
leucopterus, less than one-fifth of an inch in length, blackish- 




The chinch-bug, Blissus leucopterus ; Ion 
short-winged forms, enlarged. 



and 



THE INSECT WORLD. 



159 



Fig. 122. 



brown in color, and with soft white wing-covers, which make it 
quite conspicuous. It feeds on grass crops of all kinds, in- 
cluding grain and corn, and causes enormous injury annually. 
It can hardly be said that we have any entirely satisfactory 
means of controlling this pest at the present time. Elaborate 
experiments have been made in some of the Central States with 
a fungous disease to which the insects are subject, but the out- 
come has hardly equalled expectations. We know positively 
that they hibernate in the adult stage, hidmg everywhere, and 
appearing in spring to oviposit just beneath the soil upon roots, 
or on stems at or above the surface. It is said that a single 
female lays about five hundred eggs. The brood becomes adult 
in midsummer, or thereabouts, and there is then a tendency 
to migrate, particularly if the original infestation was in wheat, 
which is by that time mature and does not suit them as food. 
Corn or any other 
grass crop in the 
vicinity is then at- 
tacked, though corn 
is favored because 
of its juiciness. 
Elaborate publica- 
tions on this insect 
and the means for 
its control have been 
issued by the United 
States Department 
of Agriculture, and 

by the Experiment Stations in Illinois, Kansas, and other States' 
in the grain and corn-raising districts of the country. The 
recommendations generally narrow down to a thorough clear- 
ing up in winter to destroy as far as may be the hibernating 
adults. When the migrations commence from wheat to corn, 
protection may often be obtained by trenching. The insects 
do not readily resort to flight even when adult, but rather march 
from field to field, and, by interposing a trench which is not 
easily crossed, and where the insects can be destroyed by means 
of tar or kerosene, fields may be protected. As this subject 
is yet under consideration by so many students, it will not be 




Chinch-bug.— a, 5, egg; c, newly-hatched larva; ^-.Z, larvae 
further advanced; g, pupa; h, leg; /, beak ; 7, tarsus. 



i6o 



AN E CON 03/7 C ENTOMOLOGY. 



necessary to go into details here. The agriculturist in the regions 
subject to chinch-bug attack should in each case inform himself 
of what results have been reached, and what recommendations 
are made by the Experiment Station in his own State. It need 
only be added that the character of the weather frequently deter- 
mines the increase of the insects, dry warm weather favoring, 
and wet cold weather being unfavorable to their development. 

In the family Coreidcs we have species of moderate or large 
size, many of them very curious in form and shape, some of them 
carnivorous, but others vegetarian and more or less injurious. 
They are oblong, rounded behind, the head rather small, with 
long antennae, and a beak of moderate length. They are flat- 
tened above, but very convex beneath, so that a section through 
the insect would show an appearance nearly resembling an equi- 
lateral triangle. The legs are usually of moderate length, but 
sometimes become curiously enlarged, the hind legs especially 
being subject to leaf-like expansions, giving the insects a decidedly 
odd and bizarre appearance. They are brown in color, some- 
times black-marked, sometimes with reddish variegations, and 
altogether, perhaps, they resemble most nearly the Reduviidcs, 
from which they are easily distinguished by the larger head and 
the longer, flattened, four-jointed beak. All 
the members of this family may be looked 
upon with suspicion, because, although a 
number of them do undoubtedly feed upon 
other insects, yet some of these very pre- 
daceous forms have also been observed feed- 
ing upon plants, and it is more than likely 
that they vary their diet as occasion serves. 
A typical representative of the injurious 
forms is the well-known "squash-bug," 
Aiiasa tristis, which attacks cucurbit vines 
of all kinds and sometimes does notable 
injury. The insect is dull grayish-brown in 
color, the tips of the wing-covers darker, 
while the edges are somewhat paler. It is 
between one-half and three-fourths of an inch in length, quite a 
ready flier, but with rather weak legs, and therefore a poor run- 
ner. It is also called the "stink-bug," because of a peculiarly 



Fig 




The squash- bug, 
tristis. 



Atiasa 



THE INSECT WORLD. 



i6i 



offensive musky odor, which is quite lasting and noticeable even 
after stained hands have been thoroughly washed. We find the 
adult late in fall, and it remains in that condition during the winter, 
under bark of trees, under rubbish, in barns and similar localities. 
A large number are destroyed by one cause or another during this 
period, but some survive, and in the spring lay upon the squash 
or other cucurbit vines patches of unusually large, almost golden- 
brown eggs. The little fellows that hatch from them are much 
shorter and broader in proportion than the adults, maturing some 
time during midsummer, and providing thus for a second genera- 
tion. Only two broods occur in the Middle States, though they 
overlap somewhat, making it appear as if breeding continued 
during the entire summer and early fall. The punctures made by 
this insect in feeding seem to have a peculiarly poisonous effect 
upon the plants, young vines especially being apt to succumb to 
even a few specimens. This is another of the cases where clean- 
liness becomes advantageous, and constitutes also a method of 
avoiding injury to a great extent. It has been found that the 
second brood does not mature until quite late in fall, and, seem- 
ingly, only those that become adult after the beginning of Sep- 
tember have any tendency to go into winter quarters. It should 
be the object of every grower afflicted by these insects to destroy 
the cucurbit vines just as soon as he has all the crop he wants from 
them. This can be done by plowing under thoroughly, or by 
raking out and burning the vines. In either case the immature 
bugs starve to death and never develop into adults. If this practice 
is followed by all growers, in localities where raising cucurbits is 
an industry, there is little danger of trouble from the insects. In 
kitchen gardens, and on a small scale, injury may be prevented 
by first picking off the bugs wherever they are noticed and, later, 
picking off those parts of the leaves containing eggs. The eggs 
are laid on the under side, and are so prominent that looking for 
them is a matter of little difficulty, no cluster escaping a more 
than casual glance. 

Now comes a series of broad, heavily-built bugs, in which the 
scutellum is greatly elongated and covers a large part of the 
abdomen. In this, the Pentatomidce^ the enlarged scutellum is 
triangular, and has a lateral groove into which the edges of the 
wing-covers fit when not in use. Here also we have some species 

II 



l62 



A TV ECONOMIC ENTOMOLOGY. 



that are predaceous and others that are plant-feeders, and, as in 
the preceding case, it is difficult to say always whether the 
species are beneficial or injurious. They will all stand watching, 
at any rate, but, fortunately, not many of them occur in great 
numbers. Perhaps the most marked exception is the ' ' harlequin 
cabbage-bug, ' ' Murgantia histrionica. This is one of the most 
serious pests to cabbage in the Southern States, being found in 

small numbers on Long 
Island, in the southern part 
of New Jersey, and then 
increasing rapidly in num- 
ber and destructiveness 
throughout the South and 
Southwest. These also win- 
ter in the adult stage, and 
egg-laying begins quite 
early in the spring. They 
are said to pass through all 
their stages in two weeks, 

Harlequin cabbage-bug, Murgantia histrion- ^^^^ j^. j-jg rcadilv SCCn 

ica.—a, b, larva and pupa ; c, d, e, eggs, natural i i • r 

size and enlarged, from side and top;/, ^, adult, that there IS rOOm for a 

number of generations in 
the course of the season. Practical experiments seem to prove 
that fighting the adults early in spring is most effective. Mus- 
tard seems to be their favorite food-plant, and it is recommended 
to plant rows of mustard between the cabbage rows for the pur- 
pose of attracting the old bugs. They can be sprayed there 
with pure kerosene, which kills them readily, and if it also kills 
the mustard, no great harm is done ; or, they can be collected in 
pans in the morning, before they have become active, and in this 
way they will be sufficiently reduced in number to prevent them 
from becoming troublesome later on. Of course this is another 
of the remedies that depends for its greatest success upon com- 
bined action. It has also been recommended that the hibernating 
bugs be trapped in early spring under turnip or cabbage leaves, 
preserved for that purpose during the winter. 

The allied family Cyd7iidcs is interesting, having the legs formed 
for digging, though otherwise resembling the preceding. Their 
food habits are not well known ; but none of them are injurious. 



Fig. 124. 




THE INSECT WORLD. 




A very curious series is the Corivielcejiidcs, or "negro-bugs," 
distinct by their usually small size, their intense black colors, 
which occasionally have a bluish or greenish 
tinge, and by their very convex form. The -^^5- 
scutellum covers nearly the entire upper surface 
of the body, and the insects are quite generally 
mistaken for small beetles. They may be found 
on plants of all kinds and sometimes in consider- 
able numbers, but noticeable injury is rarely in- 
flicted. Their most disagreeable habit is laying Fiea-iike negro- 
eggs on a number of the small fruits, like black- ^^^armZx^xz^l 
berry and raspberry, and if these are crushed 
in eating, an excessively disagreeable, ' ' bed-buggy' ' taste is 
noticed. 

The last family of this order to which we call attention, even 
though it is not injurious, is the Scutelleridce , the species of 
which are yet more oval, though perhaps less convex than the 
preceding. As before, the scutellum covers nearly the whole 
of the abdomen, but these species are often brightly colored. 
They are moderate in size or quite large, and are southern and 
western, a few species only being rarely found northward. 

Taking it altogether we have in the heteropterous series of the 
Hemiptera forms which gain their food by sucking juices, and in 
perhaps the majority of instances the juices of plants. Yet, 
taking it altogether, there are comparatively few seriously injuri- 
ous species, and, if we except the " chinch-bug," they do not 
begin to compare with their homopterous brethren in the amount 
of injury they do to farm crops. The insects are nearly all diffi- 
cult to deal with, as they resist insecticides quite strongly. No 
weak mixtures affect them, and even the kerosene emulsion 
cannot be diluted more than three or four times, if any large 
proportion of adults are to be killed. Stomach poisons are out 
of the question, of course, and we are thus reduced to mechani- 
cal means or farm practice to avoid trouble. These methods 
have been indicated in the course of the chapter, and need no 
formal repetition. 



164 



AN ECONOMIC ENTOMOLOGY. 



CHAPTER VI. 



THE COLEOPTERA OR BEETLES. 



Fig. 126. 



The Coleoptera, ' ' horn-winged' ' insects, or beetles, are dis- 
tinguished by the hard, horny, or tough, leathery texture of the 
fore-wings or elytra, which meet in a straight line down the 
middle of the back, and are not used in flight, serving as wing- 
covers only. They vary greatly, and are numerous in specimens 
and species, over twelve thousand kinds having been described 
from the United States and British America alone. They are as 
diverse in habit as in size and form, some being among the most 
dangerous enemies of agriculture, while others are among the 
most useful. 

It seems at first sight as if the recognition of beneficial or in- 
jurious forms among so many would prove a hopeless task, and 
yet we find it in most cases possible to say at a glance whether a 
given specimen is herbivorous, i.e., plant- 
feeding, or carnivorous, i.e., flesh-feeding 
and predaceous. 

All beetles are mandibulate and chew their 
food ; but in one series the head is more or 
less prolonged into a snout or beak, at the 
end of which the much reduced mouth parts 
are situated. These are the Rhynchophora, 
or "snout-beetles," all of which are plant- 
feeders and injurious, or likely to prove so. 

The true Coleoptera, in which the head is 
not prolonged into a beak, we can separate 
by the structure of the tarsi or feet. Nor- 
mally there are five joints or segments to 
each pair of feet ; but there are many de- 
partures from this rule, one large series having four apparent 
joints only, of which the third is lobed or deeply notched. The 
species in which this structure obtains are all plant-feeders ; 
either on leaves or in stems, trunks, branches, or roots ; often 
in dead, though more usually in living tissue. In no other case 




Tarsi in Coleoptera.— 
c, normally five-jointed ; 

b, normally four-jointed ; 

c, four-jointed, with the 
third joint deeply lobed, 
from side and from above. 



THE INSECT WORLD. 



is the structure of the tarsi alone an absolute guide to the food 
habits ; but if we turn to the antennae or feelers we obtain an 
additional basis. 

Roughly speaking, the beetles, other than those already sepa- 
rated off, may be divided into filicornia, or those in which the 
antennae are more or less thread-like, and which are usually car- 
nivorous ; clavicornia, in which they enlarge toward the tip or 
terminate in a more or less marked club, which are rarely carniv- 
orous and usually scavengers ; serricor7iia, where the joints are 
somewhat flattened and widen toward the tip, so that one mar- 
gin resembles to a greater or less degree the toothed edge of a 
saw, which are feeders upon vegetation, as a rule ; larnelli- 
cornia, in which there is a leaf-like club at tip, which are always 
vegetable feeders ; and monilicornia, where the joints are more 
or less oval or globular and set so as to appear like a string of 
beads. 

The terms filicornia and monilicornia are not in general use at 
the present time. The latter series has the hind tarsi four-jointed 
and the anterior and middle five-jointed, whence they are now 
termed Hetero^nera, or "different-jointed," to distinguish them 
from the Isomera,'' where all feet have the same number of 
segments. But they are not uniform in habit, so that the deter- 
mination of an insect as belonging to this heteromerous series 
does not at once determine whether it is friend or foe. For the 
Jilicomia the term Adephaga is used, from the usually predaceous 
habits. 

Following the usual order of systematic arrangement, a com- 
prehensive statement of the differences is as follows : 

I. Series with the head not prolonged into a snout, true Coleoptera. 

a, The antennae filiform, or thread-like, the tarsi with five joints on 

all feet Adephaga. 

b, The antennae thickening outwardly into a more or less well-formed 

club, tarsi with an equal though varying number of joints on 
all feet Clavicornia, 

c, The antennae serrate or saw-toothed, the tarsi usually five- 

jointed Serricornia. 

d, The antennae with a lamellate or leaf-like club at tip, the tarsi 

five-jointed Lamellicornia. 

e, The antennae somewhat variable, the tarsi four-jointed, the third 

deeply lobed or cleft Phytophaga. 



i66 



AJV ECONOMIC ENTOMOLOGY. 



The antenna variable, though usually moniliform ; fore and middle 
tarsi five-jointed, hind tarsi four-jointed .... Heteromera. 
2. Series with the head prolonged into a more or less prominent snout, 
hence called snout-beetles or weevils Rhynchophora. 

In the Adephaga there are many species of predaceous habit 
in the larval as well as adult stage, of which a few more common 
types may serve as examples. 

The "tiger-beetles," or CicijidelidcB , are moderately large, 
very active and graceful species, that run rapidly and fly readily. 
Most of them frequent sandy or open spaces, their colors often 
matching their surroundings with marvellous accuracy. On the 
seashore they are white, or gray with white hairs and lines, and 
on the marshes or mud-flats the prevailing colors are dull mouse- 
gray, without contrasting lines. Early in spring a bright-green 
species is found at the margin of woods or in shaded lanes, promi- 
nent on the bare ground for an instant, but lost to sight at once, 
when startled, in a tuft of grass or on a moss-covered stone or 
log. 

The larvae are uncouth creatures, rarely seen unless sought for. 
They make vertical burrows in sandy soil or along roads, and 
there wait for passing prey, their round flat head closing the 
opening completely, while their eyes are so set as to command 
the near surroundings. They are humped posteriorh^ and on 
the hump curved spines are set, which may be forced into the 
burrow wall to maintain a position at any height, and to resist 
without effort any ordinary attempt to pull them out of their den. 
Though these "tigers" are exceedingly voracious, they are of 
little benefit to the agriculturist, because they do not frequent 
cultivated fields or orchards. 

The CarabiddB, or "ground-beetles," run to black and brown 
colors without prominent markings, and are usually more or less 
flattened. They Hve under stones, sticks, leaves, or shelter of 
any kind, in fields and along the edges of woods, more rarely in 
the woods themselves, and sometimes under loose bark or even 
among leaves. They are of a retiring disposition, and seldom 
stir abroad until after dark, when the majority fly readily. Many 
of them are attracted to light, and are recognizable, ^vhen they 
strike the table or other flat surface, by the rapidity with which 
they run, by their prominent mandibles, and slender, moderately- 



Fig. 129. Fig. 133. Fig. 130. 




Fig. 131. Fig. 138. Fig. 128. Fig. 127. Fig. 132. 




Fig. 137. 




Fig. 135. Fig. 134. Fig. 136. 




Tiger-beetles and ground-beetles. — Fig. 127, larva of Cicindela. Fig. 128, head of 
Cicindela, to show mandible. Fig. 129, C. generosa. Fig. 130, C. purpurea. Fig. 131, 
C. sexguttata. Fig. 132, C. repanda. Fig. 133, Calosoma calidum and its larva. Fig. 134, 
C. scrutator. Fig. 135, Brachinus fumans. Fig. 136, Harpahis caliginosus. Fig. 137, 
larva of Harpalus, devouring larva of plum-curculio. Fig. 138, Lebia grandis. All 
except Fig. 135 about natural size. 

167 



i68 



AN ECONOMIC ENTOMOLOGY. 



long antennae. Some of them are dirty clay-yellow in color, with 
the disk of the wing-covers marked with black or brown. 

We have only a few species belonging to the genera Caj-abiis 
and Calosoma, in marked contrast to the great number found in 
European fields, none of our large forms having found life in 
tilled land tolerable. The species of Calosoma often ascend trees 
and feed on caterpillars, the term "caterpillar hunters" having 
been in consequence applied to them ; but some of the smaller 
species also have similar habits. In orchards they are som.etimes 
found hidden just beneath the surface of the soil, close to the base 
of the trees. 

The " Bombardier beetles," belonging to the genus Brachhius, 
may be especially mentioned because of their peculiar power of 
emitting a puff of bluish vapor from the anus when suddenly dis- 
turbed. They have the body, head, and thorax reddish, the 
elytra blue, and are found under stones along the edges of roads 
and near woodlands, or, more rarely, in the loose rubbish at the 
base of trees. 

A series of very much flattened species frequents flowers, feeding 
upon the minute insects abundant there, and these are sometimes 
red and blue, or even brilliant metalHc green, with the wing- 
covers squarely cut ofl behind so as to expose the tip of the 
abdomen. Among these is the Lebia grandis, a moderate-sized 
species, with yellowish-red head and thorax, and blue elytra, that 
makes itself useful by feeding upon the eggs and larvae of the 
Colorado potato-beetle. 

But the great majority of our species are moderate in size, and 
of powerful build, black or nearly so, lurking under all sorts of 
rubbish in field and orchard, frequently in large numbers, yet 
rarely observed, and ready at all times to pounce upon any soft- 
bodied larvae that come within their range of vision. These 
belong to the genera Pterostichus, Ajiisodactylus, Amara, Har- 
palus, Agonoderus, or their close allies, and they are decidedly 
important factors in checking the undue increase of certain species 
which must go underground to complete their transformations, 
— the " plum-curculio," " pear-midge," and others. Their 
larvae are even more retiring and less frequently seen, but live 
in similar situations. They are slender, more or less flattened, 
of nearly equal width, with six short legs, a pair of prominent 



THE INSECT WORLD. 



169 



Fig 



mandibles, and a pair of bristly processes at the anal end of the 
body. 

Two other families belonging to the Adephaga are aquatic in 
the larval as well as adult stage, and are as predaceous as their 
terrestrial relatives. 
The DytiscidcB and 
their larvae have been 
termed 'Svater- 
tigers," and the larger 
species attack small 
fish as well as insects. 
In form they are oval 
and somewhat flat- 
tened, and they may 
often be seen rising to 
the surface of quiet 
pools or spring-holes, 
head down, releasing 
a bubble of air, and 
then, after remaining 
for a little time, with 
the anal extremity 
above the surface, 
again starting for the 
bottom. There is con- 
siderable space between the wing-covers and the abdomen in 
these species, and this is utilized as a reservoir for the air which 
the insect breathes beneath the surface. When it becomes impure 
the beetle rises again to the surface, releases the vitiated air, and 
takes in a new supply. 

This ends the series Adephaga^ and no practically injurious 
forms exist in it ; all are more or less beneficial by reason of their 
predaceous habits. Under some circumstances a few of the 
species eat pollen, and after midsummer some have been found 
gnawing grass-seed ; one or two species have even been found 
eating into the kernels of corn, so there appears to be a tendency 
to vary to a vegetable diet under certain conditions. In fact it 
has been demonstrated that in many species some vegetable 
matter is regularly eaten ; yet, as this feeding is not of a character 




A water-tiger, Dytiscus marginalis.—a, larva, devour- 
ing an Agrion larva ; b, pupa ; c, male beetle, the elytra 
of the female at side ; d, anterior tarsus of the male, yviib. 
sucking disks ; e, tarsus of the female : a, b, c, about 
natural size. 



AlV ECONOMIC ENTOiMOLOGY. 



injurious to the agriculturist, the series may be, as a whole, 
accounted beneficial. 

In the Clavicornia we have a much greater diversity of form, 
and many families, differing widely in habit, and some of these are 
economically important. 

Fig. 140. 




A water-scavenger, Hydrophilus triangularis. — a, the larva ; b, male adult ; c, pupa ; d, 
opened, and e, closed egg case ; y to i, enlarged structural details of the adult. 

First, joining to the aquatic Adephaga there are two families 
of aquatic Clavicornia, the HydrophilidcB, or "water-scavengers," 
and the Gyn^inidce, or "whirligig-beetles." 
The former resemble the water-tigers in 
general appearance, but are more convex 
above and more flattened below, usually with 
brightly-polished wing-covers. The differ- 
ence in the form of the antennae will easily 
prevent confusing the families. 

The Gyrinidiz cannot be mistaken. They 
^1,,^' " are black or bronzed, oval, shining, with un- 
usually long forelegs, and disport themselves 
in swarms on the surface of ponds and streams, 
darting here and there, or sometimes swim- 
ming rapidly in large or small, regular or 
irregular circles, whence they derive their "whirligig" appella- 
tion. They are predaceous in all stages, but of no agricultural 
value from their strictly aquatic habits. 




A ■' whirligig"-beetle 
(1) and its larva (2) : nat- 
ural size. 



THE INSECT WORLD. 



171 



The family SilphidcB, containing what are popularly known as 
"carrion" and "burying beetles," is in sharp contrast to any- 
thing heretofore spoken of, and here the antennae are capitate, — 
i.e., terminated by a spherical or ovate knob abruptly formed, 
like a head. The beetles are usually found on or about carrion 
of all kinds, though some of the smaller forms live in decaying 
fungi. In the large species there are two distinct types, repre- 
sented on the one hand by the genus Silpha, in which the species 



Fig. 142. 




a be 

Carrion beetles.— c, Necrophorus americatia ; b, larva of Silpha lapponica ; c, Silpha 

americana. 



are much flattened and proportionately very broad, with small 
heads, and on the other by the genus Necrophorus, in which the 
species are much more heavily built, narrower, not flattened, and 
with large heads. These are the true ' ' burying' ' beetles, and 
derive the name from their habit of excavating beneath small 
dead animals and gradually sinking them below the surface level. 
Then the females lay their eggs in and the larvae live upon the 
buried and decaying creatures. The other carrion beetles make 
no pretence of burying their prey, but lay their eggs at once, 
and the larvae feed upon it from below, usually making a short 
burrow in the soil for shelter, though this is not universal. In 
both types the larvae are black, flattened, broadly oval, and with 



172 



AJV ECONOMIC ENTOMOLOGY. 



Fig. 143. 




Rove-beetle and its larva. 



the segments distinctly marked at the edges. These beetles have 
the sense of smell wonderfully developed, and I have frequently 
covered a small, freshly-killed animal with a box of wood or 
tin, only to find next morning a number of the insects beneath 
it. The species are generally nocturnal, and as scavengers are 
useful, or at least innoxious. 

The large series of "rove-beetles," or StaphylinidcE, is pecu- 
liar in the short wing-covers, which leave more than half the 
abdomen exposed. The species are always 
long and comparatively narrow, usually 
with a large head and well-developed man- 
dibles, and live in all sorts of fermenting, 
decaying, or excrementitious animal or 
vegetable matter. Most of them are small, 
and many are found beneath bark, in fer- 
menting sap, or in fungi, while the larger 
forms are often found in or under animal 
excrement, or on or under carrion. In 
short, the species are scavengers, with a 
tendency to a predatory habit in some cases, and never any 
disposition to feed upon growing vegetation. They may thus be 
accounted either actively beneficial or at least not injurious, and 
as scavengers they aid in reducing organic matter into condition 
for assimilation by plant-life. 

The next family meriting attention from its economic interest 
is the CoccinellidcB^ or, as the species are commonly termed, 
"lady-bugs" or "lady-birds." Scientifically these insects are 
distinguished by having the tarsi three-jointed only ; but practi- 
cally they are recognizable by their oval or round form, — always 
convex, sometimes almost hemispherical, — and by their colors, 
which are either of some shade of red with black spots and 
markings, or black, with red or yellow spots. The species are 
never large, sometimes very small ; but in almost all cases are 
predaceous, their prey consisting chiefly of plant-lice or scale 
insects. The larvae, which have the same feeding habits, are 
usually fusiform, with a small head and quite long legs. They 
are often prettily colored, sometimes with spiny warts or pro- 
cesses, and may be seen running about wherever plant-lice 
abound. Patches of from fifteen to forty of the yellow eggs 



174 



AN ECONOMIC ENTOMOLOGY. 



laid by the beetles are often seen in abundance on infested 
plants. 

The species of Megilla and Hippodamia are more oval and 
less convex than usual, and some of them have been found feed- 
ing" on pollen or even seeds, when their natural prey was scarce ; 
yet I have observed these same species doing yeoman's work in 
the destruction of plant-lice on melon-vines. 

The genera Adalia and Coccijiella contain the more hemispher- 
ical types, and among the most common are the " 9-spotted lady- 
bird," Coccinella g-7iotata, which is one of the larger species, and 
the " 2-spotted lady-bird," Adalia bipuncta, which is the smaller 
and perhaps most frequently seen in gardens and even houses. 
Among the largest of our forms is the " 15-spotted lady-bird," 
Anatis i^-pundata, interesting from its color variations, ranging 
from creamy-white with distinct black spots to uniform mahogany 
brown. 

Opening quite a distinct series of species, which are black, 
with red or yellow spots, is the " twice-stabbed" lady-bird, Chilo- 
corus bivulneriis, in which the larva is spiny. This is black, 
almost hemispherical, with a somewhat ovate red spot on each 
wing-cover, and is found throughout the United States. Its 
chief food, in the larval as well as the adult stage, consists of scale 
insects, and it is one of the most effective checks on that kind of 
plant pest, under favorable circumstances ridding individual trees 
completely. 

We have other similar but smaller species, sometimes with 
numerous yellow spots on the wing-covers, and most of them 
have the scale-eating habit to a greater or less extent. The 
species of Pejitilia are uniformly black and very small, less in 
size than most of the scale insects upon which they prey ; but 
they, as well as their minute spiny larvae, are great feeders, espe- 
cially upon the eggs and larvae. The destructive San Jos6 scale 
has no more persistent or effective enemy than this kind of small 
lady-bird. 

The species of Scymnus are also small, usually recognizable by 
their fine pubescent or hairy clothing and black colors. There 
is a tendency to red-tipped wing-covers or red thorax, and these 
forms also prey largely upon scales. To this family belong the 
Australian species of Vedalia, Orcus, and Rhizobius, introduced 



THE INSECT WORLD. 



175 



Fig. 150. 



to destroy the also imported ' ' cottony cushion-scale, ' ' Ice^ya 
purchasi. The relation of these species has been already dis- 
cussed when speaking of the scale, 
and will be again referred to in Part 
III. of this work. 

There are few rules without excep- 
tions, and so we find sinners among 
the lady-birds also, — all belonging to 
the genus Epilach7ie. The species 
are large, hemispherical, and yellow, 
with black spots. The larvae are 
also yellow, elongate oval, with long 
branched spines. E. borealis is the 
Northern and Eastern species at- 
tacking cucumber, melon, and sim- 
ilar vines, while E. corrupta is found 
in the West and Southwest, injuring 
beans. A curious feature in E. borealis 
is the manner in which the adult 
marks out a circle at the edge of a 
leaf and feeds within it until all usable 
tissue is exhausted, before proceeding 
to another place to repeat the opera- 
tion. 

As these injurious species feed 
openly in all stages, they can be 
reached without trouble by any of the 
arsenites. 

The family ErotylidcB contains some 
very prettily marked species of quite 
diverse forms, most of which feed in 
or on fungi, or may be found under 
loose bark, and are, therefore, innox- 
ious. In the genus La7iguria, how- 
ever, we find an exception, since their 
larvae live in the stems of clover and 
other plants. They are very slender, 
almost cylindrical, from one-fourth to 
one-half an inch in length, and have the wing-covers blue or 




Epilachne corrupta.— A, adult; 
B, pupa; C, larva; D, injury on 
bean. 



176 



AN ECONOMIC ENTOMOLOGY. 



black, while the thorax is usually more or less red or yellow. 
Our common clover-feeding species is L. vwzardi. It is rarely 
that any species becomes abundant enough to do noticeable in- 



FiG. 151. 




Langiiria vwzardi. — a, egg ; b, larva in clover stem ; c, larva ; d, pupa ; e, adult. 

jury ; but in clover, if a sufficiently large infested area occurs, 
prompt close cutting or turning under the sod will be most 
effective in checking present and preventing future injury. 

The OicujidcB are elongate and very much flattened beetles, 
fitted to live under bark of trees or in the narrow crevices where 

Fig. 152. 




Silvanus stirinamensis. — a, beetle; b, pupa; c, larva. 



they are usually found. Some of the species of Silva7i2is, notably 
S. suri7iamensis , a brown species, hardly more than one- eighth 



THE INSECT WORLD. 



177 



inch in length, with the edges of the thorax toothed, are excep- 
tions in habit, though not in form, and often infest granaries, 
mills, and stables. The adult as well as its larva is frequently 
found in mangers or in neglected little masses of meal, flour, or 
grain, in which they breed. Cleanliness is the best remedy when 
these insects become abundant : allow no partly emptied boxes 
or bags to lie about, keep current supplies covered or tied up, 
and sweep out corners at short intervals. Bisulphide of carbon, 
where its application is possible, is an effective remedy, readily 
destroying the beetles as well as their larvae. 



Fig. 153. Fig. 154- Fig- i55- 




Atomaria ephippiata. Corticaria pumila. Cryptophagus croceus. 



There are other, yet smaller beetles found in similar situations 
in less numbers, and these belong to allied families. They may 
be brown, not more than one-sixteenth of an inch in length, with 
an oval body and narrow thorax, and then they are probably 
species of Corticar^ia ; they may be of similar color, but with the 
thorax and body more nearly of a width, and then they may 
belong to Atomaria or Cryptophagus ; or they may be equally 
minute but flattened, black, with red or yellow spots or bands on 
the elytra, and then they probably belong to Litai-gus. All may 
be treated as above suggested. 

We have a series of robust, small or moderate-sized beetles, 
usually broad but sometimes narrowly oval, with small retracted 
head, slender, moderately long legs, capable of being so closely 
folded upon the breast as to be almost invisible, and with the 
unpleasant habit of feeding upon dried animal substances, such 
as furs, skins, woollens, museum specimens, meats, and the like. 

12 



178 



AN ECONOMIC ENTOMOLOGY. 



Fig. 156. 



These belong to the family Dermestid^E, which contains such 
nuisances as the "larder-beetles," "carpet-beetles,'' and "mu- 
seum-beetles." The elytra, which cover 
the abdomen completely, are black or 
gray, usually ornamented with white or 
colored scales, which sometimes form 
quite pretty markings. 

The "larder-beetle," or "bacon- 
beetle," Dermestes lardarius, is rather 
more than one-fourth of an inch long, 
and easily recognizable by having the 
anterior half of the wing- covers pale 
brown or yellowish, its livery else being 




of a sombre black or dark e: 



ray. 



The 



The larder-beetle, Dermes- 
tes lardariiis. — a, larva; b, a 
single hair from larva ; c, adult 
beetle. 



larva is nearly half an inch in length, 
rather narrow yet plump, and clothed 
with rather dense, long, brown hairs. 
It feeds on stored provisions of all 
kinds, on hides, skins, or other similar substances, and is occa- 
sionally quite troublesome in smoke-houses. Cleanliness, plenty 
of air, tight receptacles, and close-meshed wire netting on the 

covers or doors of 
Fig. 157. pantries and boxes 

are the best prevent- 
ives, supplemented 
by destruction of the 
beetles and larvae 
wherever noticed. 
Good results are 
often obtained by 
leaving a tempting 
bit in an exposed 
position, which will 
act as a trap, attract- 
ing beetles and larvae 
where they can be 
easily found and destroyed. Several other species, similar in 
size but differently marked, have similar habits, and among 
them the "leather-beetle," D. vulpimts, has been responsible 




Leather-beetle, Dermestes zmlpinus.—a, larva; h, pupa: 
k, adult ; d to 7', details of larva. 



THE INSECT WORLD. 



179 



for much mischief in tanneries and factories producing leather 
goods. Where fumigation is possible, bisulphide of carbon may 
be employed with good effect, while gasoline readily destroys 
both beetles and lar^-ae where it can be brought into contact with 
them. 

Larvae similar to those above described, but much smaller, are 
often found in museum collections on mounted animals, eating 
the skins, hair, and feathers, and in entomological collections, 
destroying the specimens entirely. The beetles from these 
larvae are smaller and more ovate, and belong to the genera 
Trogoderma or Megatoma. They are often found on flowers 



Fig. 158. 




The carpet-beetle, Anthreniis scrophularicE . — a, larva ; b, larval skin split to expose 
the pupa within it ; c, pupa ; d, beetle. 



in this stage, in company with species of Anthre7ius, in which 
the larvae are stouter, more clumsy, equally clothed with hairs, 
but with the ability to expand two larger tufts posteriorly. 
Anthrenus also contains museum pests as well as the ' ' carpet- 
beetle," A. scrophularia, which feeds on woollens in the larval 
condition, and is then better known as the " buffalo-moth," from 
its tufted appearance. The beetles are very broadly oval, with 
brick-red scales along the middle of the wing-covers, and two 
irregular white scaly bands transversely across the elytra. I have 
found them very early in spring under the loose bark of trees 
where they had passed the winter. Later they fly into open 
windows, and lay their eggs wherever they find a supply of 



i8o 



AN ECO AW MIC ENTOMOLOGY. 



woollens. For this household pest a liberal use of napthaline in 
crystals or balls, in trunks and closets, is advisable as a pre- 
ventive. Where woollen garments are to be stored through 
the summer they should be first thoroughly beaten or brushed 
and sunned out, then wrapped in stout paper with the edges 
pasted, or in cotton sheeting well sewed. Then, if laid away 
in boxes or trunks, or hung in closets with napthaline crystals 
between the layers, or on the shelves, or among the bundles, 
little danger is to be feared. Where carpets are infested, it is 
best to have them taken up, thoroughly beaten and cleaned, and 
the floors thoroughly cleansed before they are relaid. Where 
this is undesirable for any reason, gasoline may be used with 
satisfactory results. Except on the cheapest fabrics it may be 
safely used in liberal quantities without danger of injuring either 
texture or colors, and wherever the liquid comes into contact 
with either beetle or larv^a it kills at once. Eggs, however, are 
not destroyed, and close watch must be kept for a week at least, 
when a second application may be found necessary to reach the 
larvae hatched since the first was made. Another method, 
almost equally good but more troublesome, is to place a wet 
cloth over the infested patches and press over it with a very hot 
fiat-iron, the object being to drive hot steam or vapor through 
the fabric and thus, practically, to cook the insects. In collec- 
tions, tight boxes or cases and a free use of napthaline or 
bisulphide of carbon, or both, are essential. 

Unity of habit in this family is marred by Byturus unicolor, 
a little yellowish species which is densely covered with short silky 
hair, and feeds in the blossoms of the red rasp- 
FiG. 159. berry, where also its eggs are laid. The larvae 
are white, nearly naked, and are found on the 
inside of the berry when picked. The species has 
not become seriously troublesome as yet, and is 
mentioned here chiefly because of its unique 
habits. 

^"^'eniarged.'''"' HistevidcB are small, oval, shining, very 

hard, black, bronzed or greenish beetles, with the 
wing-covers cut off squarely behind, leaving the last segments 
of the abdomen exposed. The legs are broad and flat, fitted for 
digging, and the head is small, yet with quite prominent sharp 




THE INSECT WORLD. 



i8i 



mandibles and capitate antennae. They are mostly scavengers, 
the larvae white and somewhat maggot-like, occurring on, in, or 
under all sorts of excrementitious or decaying animal or vegetable 

Fig. i6o. 





Hister arcuatus and Hister bimaculatus , much enlarged. 

matter, in over-ripe fungi or fruit, or under the loose bark of 
trees. They are of no practical importance to the agriculturist. 

The Nitidulidcs, or " sap-beetles," are also small, more or less 
flattened, always with the tip of the abdomen exposed beyond the 
wing-covers, and with the 



legs not specialized for 
digging purposes. They 
feed in all stages on de- 
caying or fermenting sap 
or fruits or in fungi, and 
some of them are found 
also on carrion. As a 
whole, while the species 
are quite numerously rep- 
resented and often seen, 



Fig 




Fig. 162. 




Carpophilus hemipterus, 
enlarged. 



Ips fasciatus and its 
larva, enlarged. 



yet they are not either markedly beneficial or injurious. 

Somewhat similar habits are met with in the TrogositidcE, 
which are also flattened creatures, most of them living under 
bark. Some of the species of Tejiebrioides , however, — black 
beetles about one-fourth of an inch in length, with square thorax 
and large head, known as " cadelles" — are found in stables, 
barns, and mills, feeding on grain, meal, and flour. They are 



l82 



AA^ ECONOMIC ENTOMOLOGY. 



rarely very numerous, and may be kept in check as recom- 
mended on a previous page for the Cucujidce. 

There are other small famihes in the clavicorn series, some of 
them interesting enough to the entomologist, but none of im- 
portance economically 
or likely to attract the 
attention of the cas- 
ual observer ; hence 
hardly subjects for de- 
scription here. 

The Serricoryiia, or 
"saw-horned" series, 
begins with the family 
DascyllidcE, contain- 
ing mostly small forms 

Tenebrioxdes corticahs, the "cadelle." — a, larva; ^. r j j j 

adult; c toy, structural details. louud ou dead or dy- 

ing trees or branches, 

in which the larvae probably live. None are of economic im- 
portance, a fact which is also true of the next family, Rhipiceridcs . 
This latter, indeed, contains only five species, all accounted 
rarities in collections, and believed to breed in cedars. 

The family ^/(2Z'm'^/<:^, "spring-beetles," "click-beetles," or 
" snapping-beetles," contains numerous troublesome forms, and 
is easily distinguishable in all its stages. The beetles have the 
prothorax very loosely jointed to the rest of the body, and on 

the under side a curved 
process fits into a cavity 
of the meso-thorax. 
When a specimen is 
placed on its back it 
bends the extremities so 

An Elater from side, to show the prosternal process. . • , n 

as to raise the middle of 
the body from the surface, and to bring the tip of the curved 
process to the edge of the cavity. A sudden release of muscular 
tension reverses matters, sends the insect into the air a few inches, 
and this "snapping" or jumping performance is repeated until 
it alights on its feet. In the larval stage the term " wire-worms" 
expresses the appearance and texture of the creature, and brings 
to mind at once an agent of destruction hardly surpassed in the 



Fig. 163. 





THE INSECT WORLD. 



insect world. Scarcely a farmer can be found who has not been 
troubled to some extent by "wire-worms," and many a remedy 
recommended as infallible has been tried and found wanting in 
actual practice. We have two series of species, one of which 



Fig. 165. Fig. 166. Fig. 167. 




Fig. 165, the eyed Elater, Alans oculatus. Fig. i66, wood-boring wire-worm, from side- 
Fig. 167, a, larva; b, adult click-beetle. 

feeds in decaying wood, the other underground on the roots of 
plants ; of these the first may be left out of consideration alto- 
gether, though in it may be found the species of Alaiis^ our 
largest and most prominent forms. The history of the subterra- 
nean species is in general as follows : The beetles appear quite 
early in spring, and may be noticed in fields where a sod has 
been turned down, during the first days of May, or earlier in the 
Southern States. They fly quite rapidly in mid-day, copulate, 
and later seek a place to oviposit. During May or June, earlier 
or later, according to the species, the eggs are laid in grass-land 
or where there are plenty of weeds, — in other words, wherever 
vegetation, especially of a grassy character, is abundant. The 
larvae hatch by midsummer and feed upon roots, growing but 
slowly and requiring, indeed, in many cases, two or three years 
to complete their development. Pupation takes place in fall, and 
usually the change to the adult also takes place before winter sets 
in, though they remain quiet, and do not voluntarily emerge 
until the spring following. 

This brief sketch does not apply in its entirety to all the sub- 
terranean forms even, but it applies very well to the majority 



i84 



AN ECONOMIC ENTOMOLOGY. 



of the injurious species. The noteworthy points are the early 
appearance and oviposition of the beetles, the two- or three-year 
life of the larva, and the pupation and change to adult in fall ; 
all of which must be considered in the methods of treatment to 
be adopted. 

The direct application of insecticides is usually impracticable, 
and the texture of the larva is so dense that most contact poisons 
are of little or no avail, salt in large quantity having proved the 
most effective. Stomach poisons are not easily applied, but on 
an experimental scale it has been found that sweetened dough 
placed beneath the surface attracts them, and this can be poi- 
soned and used as a trap. Practically, methods of cultivation 
calculated to avoid injury are most satisfactory. Grass land 
known to be infested should be plowed in fall, and while this will 
not destroy any large proportion of the larvae, it will kill most of 
the pupae and beetles then in the ground, so if the practice be 
continued for a series of years the insects will be gradually run 
out. Wherever feasible, crimson clover should be used as a 
sod crop, as this is sown in late summer after the beetles have 
oviposited and may be harvested and plowed under shortly after 
the beetles have laid eggs, practically preventing the develop- 
ment of the larvae, especially if a crop little or not at all subject 
to wire-worms follows the clover. In fact, frequent change of 
crops is a most satisfactory measure if the land be not allowed to 
remain in grass more than one year, and if corn or potatoes do 
not directly follow the sod. In light soil the salty fertilizers ex- 
ercise a very beneficial effect when properly applied, and some- 
times an advantage may be gained by keeping the land in sod as 
long as possible, where grass is needed as a crop. When it has 
" run out," plow in fall ; in spring, after cultivating and prepar- 
ing for the new crop, fertilize heavily, using kainit for potash and 
nitrate of soda, so far as possible, for nitrogen. At least one 
thousand pounds of kainit per acre should be used, and this 
seems exceedingly disagreeable to the insects at all ages, and 
fatal to the younger forms. Conditions vary so much in different 
parts of the country, and rotations are so diverse in character, 
that it is impossible to suggest any course that will be universally 
appHcable, except the fall plowing. The suggestions above made 
should be sufficient, however, to guide the intelligent farmer in 



THE INSECT WORLD. 



185 



adopting the practice best suited to secure exemption in his case. 
It may be added, however, that the fertiHzers will not prove satis- 
factory unless applied as directed, — in one heavy application 
and when the ground is bare. 

The species of the family Buprestidce resemble the click- 
beetles in general form, but the prothorax is firmly articulated to 
the rest of the body, so that the insects have no ''springing" 
powers, and the colors are metallic. The beetles vary much in 
appearance, but the larv^ae resemble each other closely, being 
always flattened in form, with greatly enlarged anterior segments. 
They are usually known as * * flat-headed borers, ' ' sometimes as 
" hammer-heads," and infest not only trees but shrubs, vines, and 
sometimes even herbaceous plants. Some of the species prefer 
dead or dying wood, some attack healthy plants 
only, while others, and perhaps the majority, are 
somewhat indifferent, yet are oftener found in 
weak than in healthy and vigorous trees. 

Our largest Eastern species belong to the 
genus Chalcophora, the larvae mostly feeding on 
conifers, though two of them feed on deciduous 
trees like the sycamore. The beetles have the 
elytra quite deeply and irregularly furrowed, while 
the colors are bronze, brown, or blackish. I have 
found the larvae in quite old and decaying logs, but they are said 
to attack healthy trees as well, and to cause occasional injury. 

The genus Dicerca contains robust species, sometimes nar- 
rowing so strongly toward the tip as to seem almost tailed 
wing-covers are decidedly convex, irregularly corru- 
gated, or even reticulated, with elevated spots, and 
the colors are bright bronze-brown, often with green- 
ish or brassy reflections. They are rarely common, 
but infest a variety of trees, among them peach, 
plum, apricot, cherry, hickory, oak, and pine. 

The genus Buprestis contains flattened species 
with even striae or ridges, and they are often of a 
brilliant blue, green, or golden metallic color, occa- 
sionally spotted and banded with yellow or brown. 
The larvae feed mostly in conifers, but some also infest deciduous 
trees, none thus far in dangerous numbers. In Melajiophila the 




Chalcophora 
giniensis. 



The 




Dicerca di- 
varicata. 



i86 



AN ECONOMIC ENTOMOLOGY. 



Fig. 170. 




The flat-head apple-borer, 
Chrysobothris femorata. — a, 
larva; 5, pupa ; d, adult. 



wing-covers are nearly smooth or with fine punctulations only, 
and the larvae also feed principally in conifers. 

In the genus Chrysobothris we have forms that are quite flat- 
tened above, the wing-covers with irregular depressions and 
elevations, the prothorax with curved 
sides and narrower behind. Here be- 
long most of the troublesome species, 
including C. femorata, the ' ' flat-headed 
apple-borer," which, despite its com- 
mon name, attacks a great variety of 
trees. The larva makes irregular chan- 
nels and chambers in the sap-wood, 
boring into the solid tissues a short dis- 
tance only, just before pupation, and 
this describes also the habits of many 
of the other species of this genus. The 
eggs are laid on the bark in June or 
July, and the larvae live from one to 
three years before coming to maturity. 
Pupation occurs shortly before the pe- 
riod at which the adults emerge. 

The genus Agrilus contains species differing from any of those 
heretofore mentioned by their slender, cylindrical form, the head 
squarely truncate, or cut off in front, the elytra much narrowed 
at tip. As a rule, the species are dull 
brownish-bronze in color, the prothorax 
sometimes brassy or red-bronzed, and 
none is better known than the * ' red- 
necked blackberry-borer," Agrilus rufi- 
collis, the author of the ' * gouty gall' ' on 
that plant. The larvae in this genus are 
unusually long and flattened, the seg- 
ments strongly marked, the "head" not 
much wider than the body, and the anal 
forks distinct, differing in each species. 
Returning to the blackberry-borer, it is 
good practice to cut out all galled canes early in spring and burn 
them. Trimming is done at this time as a matter of regular 
cultivation, and the galls are then easily seen. No "galled" 



Fig 




Blackberry - cane borer 
Agrilus ruficollis. — b, larva 
c, adult. 



THE INSECT WORLD. 



187 



cane ever ripens a fair set of berries, and it might as well be cut 
out at once. Another satisfactory method is to cut off all the 
new shoots at the surface of the ground about the end of June. 
At this time all the beetles have laid their eggs, and the shoots 
which come up in July cannot become infested. The best results 
will be obtained by combining both methods. Cutting the new 



Fig. 172. 




Blackberry-gall maker. — a, gall just beginning to form over recent borings ; h, section 
through an old stem to show the character of the gall. 

shoots causes the death of the young larvae, which are unable to 
subsist on dead wood, and being footless are unable to migrate 
to new stalks. 

Another species of Agrilus seriously injurious in parts of the 
Eastern United States is the "sinuate pear-borer," A. sinuatus, 
imported from Europe within recent years. This feeds between 
bark and wood in pear-trees, making immensely long zig-zag 
galleries, finally girdling the tree and killing it. It lives two 
years in the larval stage. 

In general we are very helpless against boring larvae once they 
get into the trunk of a tree. Cutting out is a tedious process, 
even if the location of the larva is easily discoverable, which it 
often is not. We must, therefore, try to prevent their entrance, 



i88 



AN ECONOMIC ENTOMOLOGY. 



and this may be done more or less completely by mechanical 
means. As against the larger species — i.e.^ against all except 
Agrilus — a wire mosquito netting loosely encircling the trunk, so 
as not to touch it anywhere, is a complete protection. The in- 
sects lay their eggs under a bark scale, or on smooth bark gnaw 
a little hole in which the egg is laid, and if access to the bark be 
prevented they seek other localities. The wire must be tied at 



Fig. 173. 




The sinuate pear-borer, Agrilus sinuatus. — a, beetle ; b, larva ; c, its anal fork ; d, 
pupal chamber with pupa in position, 

the top to prevent beetles getting under it, and must extend 
underground an inch or so. In this way we not only prevent 
new infestation, but any beetles that may emerge from the trunk 
will be hopelessly imprisoned and will die without a chance to 
reproduce. 

Instead of wire netting, tarred paper or even newspapers 
tightly wrapped around the trunk to the branches will answer 
an excellent purpose, needing renewal each year, however, where 
the wire netting lasts several seasons. Thorough whitewashing 



THE INSECT WORLD. 



offers a large measure of protection, since the adults will not vol- 
untarily eat through a coat of it, and the larvae cannot do so 




Work of the sinuate pear-borer on a Bartlett pear-tree : about one-fourth natural size. 

when first they emerge from the egg. The whitewash can be 



190 



AA^ ECONOMIC ENTOMOLOGY. 



applied with a knapsack pump through a Vermorel nozzle, and 
a little Paris green adds greatly to its effectiveness. It should 
be renewed every week or two until the middle of July, when the 
danger from these flat-headed borers may be considered at an 
end, and it has the advantage of protecting the branches as well 
as the trunk. The admixture of a little glue or salt wiU improve 
its adhesive and lasting qualities. 

A strong fish-oil soap, say one pound in one gallon of water, 
is also effective and may be applied in the same manner. It 
forms a film of soap over the bark, and is repellent to the beetles 
as well as fatal to the young larvae. The admixture of an ounce 
of crude carbolic acid to a gallon of suds is advantageous. This 
mixture should not be applied to leaves or on young shoots, 
as it would probably cause injury. As these methods are all 
preventive rather than remedial, they must be promptly and 
thoroughly applied, and success will be in proportion to the 
thoroughness with which the work is done. Instead of any of 
the preceding methods, "insect lime" or "dendrolene" may 
be with proper precautions employed on the trunks and larger 
branches, and, practically, this is the best material for use against 
the "sinuate pear-borer." It can be easily applied, remains 
effective for weeks, and one application, properly made at the 
right time, will protect the trees for the season. As against the 
pear-borer, it should be applied not later than May 15th, and 



are no species injurious to vegetation, though, under the name 
"fire-flies," some of them are well known. The beetles are 
usually slender, somewhat flattened above, with a more or less 
retracted head, and are of a soft leathery texture. The ' ' fire- 




FiG. 175. 



kept intact until June 
15th, when all danger 
from that pest is over. 
Reference should be 
made to the chapters 
on insecticides and 
preventives for further 
details as to applica- 
tions. 



Fire-fly, Photinus pyralis.—a, larva ; b, pupa in cell ; 
c, adult ; dto/, structural details of larva. 



In the next series, 
the Lampyridce, there 



THE INSECT WORLD. 



191 



flies " are first noticed in June in the more northern and central 
portions of the United States, and have the terminal segments 
of the abdomen on the under side of a bright sulphur-yellow 
color, which at the will of the insect glows with a phosphorescent 
light of considerable illuminating power. They hide during the 
day on the foliage of plants or in crevices, and begin their flight 
with the deepening of the twilight. In some species the female 
is without wings and remains on the ground among the grass — 
the "glow-worm." The larvae are predaceous, and some of 
them live on snails. 

Belonging to the same family, but of a diurnal habit and with- 
out the illuminating power, are the "soldier-beetles," belonging 
to the genera Chauliogna- 
thus and Telephorus, dis- 
tinguished also by having 
a more prominent head 
and large, round eyes. 
These may be found on 
flowers, where they prob- 
ably feed on pollen, but 
are of direct benefit by 
aiding in pollination. The 
lar\-ae are even more de- 
cidedly useful, being predaceous and feeding largely on soft- 
bodied grubs and the like. They are long and slender, flattened 
above and somewhat narrowed at each end, or fusiform, the 
edges of the segments quite prominently marked. They are 
especially effective against such creatures as the larvse of the plum 
curculio when they enter the ground to pupate, and a large pro- 
portion are thus disposed of annually. 

The species belonging to the family MalachiidcB resemble the 
Lampyrids in the soft body texture and leathery wing- covers, 
but they are much shorter and broader, the broadest part of the 
body coming near the end of the wing-covers. The antennae 
are short, a little enlarged at the tip, and often curiously 
knotted in the male. Many of the species have soft, orange- 
colored vesicles, capable of being protruded from the side of 
the body. They are usually found on flowers and feed on other 
insects or insect eggs, probably doing much good in this way. 



Fig. 176. 




Soldier-beetle, Chauliognathus pennsylvanicus. 
—a, larva; b, its head enlarged; c to h, struc- 
tural details ; i, beetle, natural size. 



192 



AX ECONOMIC ENTOMOLOGY. 



The larvae of only a few species are known, and these are pre- 
daceous. 

Next come the Cleridcs, many of which are also flower-beetles, 
but with longer legs, more prominently enlarged antennae, more 

slender cylindrical form, and much 
Fig. 177. firmer texture. They are bright 

colored, as a rule, often prettily 
banded, and sometimes quite abun- 
dant. Many species are found on 





the trunks of trees, running about rapidly and somewhat resem- 
bling ants. Their larvae in such cases prey upon wood-boring 
insects, principally such as live in sap-wood, and they are slender, 

with short legs and a 
Fig. 179. prominent, somewhat 




pointed head. They are 
extremely useful in keep- 
ing in check bark-beetles 
and other borers, and are 
thus worthy of our dis- 
tinguished consideration. 



Red-legged ham-beetle, Corynetes rufipes-a Most of the Other SpCcicS 
larva; pupa ; c, cocoon ; a, e, beetle, enlarged ^ 
and natural size; /toy, structural details. are also predaCCOUS in 

the larval stage, but 
hardly beneficial, since they live in the nests of bees, devouring 
both the larvae and the food stored for them. Clerus apivorus 



THE INSECT WORLD. 



193 



infests the hives of the common honey-bee, and is more or less 
of a nuisance in some locaHties. 

The almost inevitable exception occurs in this family also, and 
the species of Corynetes, blue or part blue and part orange in 
color, live upon dead or dry animal matter, often attacking pro- 
visions. The "red-legged ham-beetle," C. rufipes, is of this 
type, and will serve to illustrate the series. The measures recom- 
mended as against the DermestidcB will answer here as well. 

In the family PtinidcB we have an aggregation of oddities diffi- 
cult of general definition, save that as a rule the species are 
small, with retracted head, more or less cylindrical firm body, and 
firm wing-covers. They feed in the larval as well as adult con- 
dition on dry animal or vegetable matter, though some species 
attack green vegetation. Many live in dead branches or twigs, 
and only a few are of sufficient interest to be especially noted. 
Of these is the "death-watch," Sitodrepa panicea, so named 
from the ticking sound frequently made by the beetle when 
working in wood, which superstition has interpreted as a warning 
of approaching death. It works also in a great variety of other 
substances, ranging from gunwads to roots of hellebore and old 
books, as a fleshy, white, grub-like larva, with a brown head and 
a surface covered with short, brown, bristle-like hairs. Where 
the nature of the article admits of such treatment, exposure to 
the fumes of bisulphide of carbon is a good remedy, as is also 
saturating with gasoline or benzine. A liberal use of paint with 
plenty of turpentine is indicated in other cases, and sometimes 
mere cleanliness following the destruction of hopelessly infested 
material will answer every purpose. 

Of the same general shape, but larger and broader, with smooth 
instead of striated wing-covers and a "humped" form, is the 
Lasioderma serricorne, popularly known as the ' ' tobacco-' ' or 
' ' cigarette-beetle. " It is a great lover of tobacco in all its forms, 
the larva relishing plug, long or fine cut, chewing or smoking, in 
cigarette, cigar, or leaf, almost equally well, and injuring it 
materially for the human user of the " weed." The matter is an 
important one to manufacturers, who deal with it in a variety of 
ways ; but it does not particularly interest the farmer. 

Among the wood-feeders the species of Bostrychus and Sin- 
oxylon are of interest, their larvae sometimes boring into fruit-trees. 

13 



Fig. i8o. 




Fig. i8o, cigars injured by the tobacco-beetle, Lasioderjua seyricorne ; holes show 
where the beetles issued. Fig. i8i, Lasioderma serricorne , from above and side. 
Fig. 182, the " death-watch," Sitodrepa patiicea, larva and beetle, from above and side; 
much enlarged. 
194 



THE INSECT WORLD. 



195 



The ' ' apple-twig borer, ' ' Aviphicerus bicaudatuSy is about the 
only species needing especial remark, and this beetle bores into 
small apple- twigs in early spring, entering close to a bud and 
making a channel several inches in length, apparently for food 
and shelter merely. It remains in these burrows a short time 
only, and then lays its eggs in the dead or dying roots of ' ' cat- 



FiG. 183. 




Apple-twig borer, Atnphicerus bicaudatus .—a, beetle, from above ; b, same, in outline, from 
side ; d, larva ; g, pupa ; h, same in larval burrow ; c, e^f, structural details. 



brier," or " greenbrier" {Smilax sp.), or in dead shoots of 
grape. The insects rarely appear in troublesome numbers, and 
then good practice is to look after neglected vineyards or grape 
tangles in near-by woods, and after brier thickets, which latter 
are an abomination at best and should be destroyed. 

There are other Serricorn families, small both in size and in 
the number of species they contain, but they are mostly rare, of 
no economic importance, and need not be referred to here even 
by name. 



196 



AA^ ECONOMIC ENTOMOLOGY. 



The next large series is the La^nellicornia, where the antennae 
terminate in a lemellate or leaf- shaped club. All the species are 
feeders upon vegetation, living or dead, green or in a stage of 
decay, and in all cases the larv^ae are ' ' white grubs, ' ' large or 
small, smooth or hairy, but always " white grubs." These can 
be generally described as having a large, yellow, or brown head, 
with prominent mandibles and long palpi, legs that are quite long, 
moderately stout, with distinct claws at the tip, usually also 



Fig. 184. 




Stag-beetles. — i, Lucanus elapJms, male; 2, L. dama, male. 



clothed with hair, a body that is cylindrical, stout, wrinkled, 
somewhat curved or even crescent-shaped, ending rather abruptly 
in a more or less enlarged, obtuse, terminal bulb. As a rule, 
the color is dirty yellowish white, but it may become pink, 
greenish, or even blackish, the hinder portion always showing 
darker because of the excrementitious mass which shows through 
the transparent tissue. 

Two families belong to this series, of which the Luca7iidce^ or 
stag-beetles, are of no economic importance though of much 



THE IX SECT WORLD. 



197 



Fig 



popular interest. They differ from the ScarabcBidcB in that the 
leaves of the club are separated and cannot be made to form 
a solid club or mass. 

Our most common "stag-beetle" is the Lucanns davia, in 
which the mandibles of the male are much enlarged and sickle- 
shaped : whence the common term " pinching-bug." It occurs 
throughout the Middle and Central States, becoming more rare 
to the North and losing interest in the South in favor of its more 
prominent relative, the L. elaphics, which in the male has man- 
dibles almost as long as itself, and branched like antlers, yielding 
in this respect, however, to its European congener, the L. cervus, 
or original "stag-beetle." Quite a different-looking creature is 
the Passahis cornuhcs, perhaps the most common of all the 
members of this family, though not always readily found. It is 
coal-black, shining, with a large square thorax and a small head 
armed with a short curved horn. All 
these species and all the lar\'ae of this 
family feed in decaying wood, and 
preferably in stumps or in roots. Thus 
their function is rather as scavengers, 
and never as destroyers of vegetable 
life. The lar\-a of the Passahis cornutus 
is interesting, because it has four legs 
only, one pair being entirely aborted. 

In the family Scai-abcsidcB the leaves 
of the antennal club are always close 
together when at rest, but can be spread 
out fan-like at the will of the insect, 
exposing the numerous sensory pittings 
with which they are closely set. The 
legs are always fitted for digging. 

At the beginning we meet a series of 
species that are scavengers, living on 
decaying or excrementitious matter. Some of them are large 
and have the curious habit of making balls of dung, in each of 
which an egg is laid. The balls are then buried beneath the 
surface, and each furnishes sufficient food to bring one larva to 
maturity. When the ball is made up on a road or other hard 
surface, the insects roll it to some more suitable place, and have 




Passahis 



cornuhis and 
pupa. 



198 



AJV ECONOMIC ENTOMOLOGY. 



therefore received the popular name 
Fig. 186. 



' tumble-bugs. ' ' The 
beetles are usually 
blackish or bronze 
brown in color, but 
sometimes bril- 
liantly metallic blue, 
green, coppery, or 
bronzed, and often 
we find in the male 
a prominent, curved 
horn on the top of 
the head, and angu- 
lar processes on the 
thorax. 

Other large or 
moderate-sized spe- 
cies make holes 
close to or under 
droppings in fields, 
working mostly at 
night, and leaving 
evidences of their 
presence in the 

shape of little piles of fresh dirt next to or even on top of the 
droppings ; cow-dung being the favorite food. These beetles 

usually have deeply striated wing- 
covers, are more stockily built 
than those previously mentioned, 
and belong mostly to the genus 
Geotrypes. 

A series of small, more slender 
or oblong, black or reddish beetles 
is often found in considerable num- 
bers burrowing in or under excre- 
ment, and these have similar habits 
and are referable to the genera 
Aphodius or Atcsnius. 

Aphodius granarius, much enlarged. r 1 1 ic ^ • 

Very oiten large, clumsy white 
grubs" are found in manure heaps, and these are larvae of 




A "tumble-bug," Copris carolma.—a, larva; b, the 
cell in which it lived ; c, pupa ; d, female beetle ; e to i, 
structural details. 



Fig. 187. 




THE INSECT WORLD. 



199 



beetles belonging to this series. None of them are in any way 
injurious. 

The exception in food habits in this family is found in the 
genus Trox, containing oblong, very convex species, with rough, 
tuberculate or pitted wing-covers, and a deeply furrowed thorax. 
They are usually more or less incrusted with dirt, are found 
feeding under old skins, bones, or hoofs, and are, as scavengers, 
at least innoxious. 

The more typical ' ' leaf-chafers' ' are of diverse forms, often 
common and economically important. Among the first we reach 



Fig. 188. 




Rose-chafer, Macrodactylus subspinosus. — a, beetle ; b, head and thorax, in outline, from 
side ; ^ to^, structural details. 

the genus Macrodactylus, of which the "rose-chafer," or 
"rose-bug" is a member. This appears in June at about the 
time roses and grapes come into blossom, and eats their flowers 
in preference to anything else. 

Occasionally, for a series of years, the insects appear in ever- 
increasing abundance, until the swarms are so great that they 
ruin not only vineyards but orchards and gardens, eating almost 
every kind of fruit and flower. In the presence of such swarms 
we are almost helpless, and insecticides are of no possible use. 
No contact poison kills them, and the arsenites or other stomach 



200 



AN ECONOMIC ENTOMOLOGY. 



poisons act too slowly, as two or three days suffice to ruin a vine- 
yard. Lest this seem strange, I will state that I have seen on 
hundreds of acres of vineyard every vine bearing multitudes, and 
every bunch of blossoms from two to ten, or even more beetles. 
I have counted over twenty on a single apple, and a full-blown 
rose may bear as many as thirty or even more. We are reduced 



Fig. 189. 




Larva, a, and pupa,/", of rose-chafer ; b to e, g, A, structural details. 

to actually collecting the specimens from the vines by means of 
funnel or umbrella-shaped collectors, adapted to the method of 
cultivation in use. They drop readily when the vines are jarred, 
and the collector should be so made as to roll them to the centre 
and into an attached pail containing kerosene. This must be 
done not only daily, but continuously for several days until the 
flight is over or the grapes have set, for well-set grapes are 
rarely eaten. Fortunately, a period of abnormal increase seems 
to be followed by a period of decrease, though the lengths of the 
periods have not been ascertained. The larvae feed in light land 
on the roots of various plants, but principally on grass. They 
pupate in spring, shortly before changing to the adult condition, 
and by ploughing infested sod at this time a large proportion can 
be destroyed. When only moderate numbers occur, Hme often 
serves to protect the plants, or, better, the Bordeaux mixture, 
which is distasteful to them. 

The "May-beetles," or "June-bugs," sometimes termed 
" cockchafers," are much larger, and mostly members of the genus 



THE INSECT WORLD. 



20I 



Lachnosterna. They fly at night, are readily attracted to light, 
and often come into rooms, clumsily and noisily bumping against 
all sorts of obstructions until they eventually strike something 
which sends them heavily to the floor. We have many species 
more or less resembUng each other, and all chestnut brown or 
yellowish in color. Some years they are very abundant and 
cause injury by eating the foliage of trees or shrubs. I have 
found them eating pieces out of the stalks of recently set apples 



Fig. 190. 




May-beetle. — i, pupa in earthen cell ; 2, larva or white grub ; 3, 4, beetle, 
from side and above. 

and pears, causing the fruit to wilt and drop. The larvae live 
on grass and other roots, and are typical ' ' white-grubs. ' ' Culti- 
vated crops are frequently attacked and much injury is some- 
times caused. The larval period has not yet been satisfactorily 
determined for all species, and varies, as does also the time for 
changing to the adult condition. Frequent rotation and fall 
ploughing are to be recommended, and where grass lands are 
infested, heavy top-dressings of kainit and nitrate of soda have 
proved beneficial. Wherever ploughing is done in infested fields, 
chickens should be encouraged to follow in the furrow to pick 
up the grubs. 

Where young trees are to be protected from the beetles, jarring 
them into an umbrella two or three times early in the evening 



202 



A A' ECOXOMIC EXTOMOLOGY. 



will prove effective, as they do not fly much after nine o'clock, 
except on unusually warm and sultry nights. 

Frequently we find on grape and Virginia-creeper, during 
midsummer, a small chafer with clay-yellow, rather shining, and 
striated wing-covers, feeding upon the leaves. This is the 
Anomala iucicola, which varies also to a shining black. It is 
occasionally numerous enough to cause notable injury, but 



Fig. 191. Fig. 192. 




Anomala Iucicola.— a, b, larva; c, pupa in Goldsmith beetle, 

lar\-al skin ; d, e,f, adult beetles. Cotalpa lajiigera. 



yields readily to any of the arsenites. The larvae live in light 
soil, feed upon the roots of grasses, and pupate in late fall, the 
adult forming soon after and remaining Avithin the cast larval 
skin until ready to emerge in early summer. 

Also found during the day on grape foliage, or flying toward 
it during early evening, is a large, shining, tan-yellow chafer, 
with eight black spots, two on the thorax and six on the wing- 
covers. This is the Pelidnota punctata, or ' ' spotted vine-chafer, ' ' 
which feeds upon the leaves, but rarely does noticeable injury. 
The lar^-se feed upon decaying roots and stumps, and I have 
taken both larva and pupa out of a rotten cedar trunk. 

Swamp-willow in the East is the food of Cotalpa lanige?^a, a 
beetle very similar in size and shape to the preceding, but of a 
beautiful shining, lemon yellow, the head glittering with a golden 
sheen, hence known as the "goldsmith beetle." Beneath it is 
of a burnished copper color, densely clothed with white woolly 
hair. It is not injurious, and mentioned here only because of its 
beauty. Some of its allies in the Southwest and in the tropics 
are of the most brilliant golden and silvery tints. 



THE INSECT WORLD, 



203 



A beetle that sometimes does considerable injury to sugar-cane 
and corn in the Southern States is the " sugar-cane beetle," Li- 
gyrus rugiceps. Unfortu- 
nately, we do not yet know "^^^ 
its entire life history, and, as 
the injuries seem to have 
been rather local and occa- 
sional, it may be that it will 
not prove of wide or gen- 
eral importance. No satis- 
factory method of dealing 
with it is known at present. 

In the genera Xylo^yctes, 
Strategics, Dynastes, and 
Phileurus, we have a series 
of species more or less 
bizarre in form, with curious 
horns and processes on 
head or thorax or both, but 
not of economic interest, 
since neither beetles nor 
larvae are found on culti- 
vated plants. Ash furnishes 
food for several of the spe- 
cies in both larval and adult 
form. 

Beginning with the genus 
Aliorhina, we have a series 
of beetles that frequent 
flowers, feeding on pollen, 
but largely repaying what 
they devour by the benefit 
they confer in pollenizing. 
Sometimes, however, they prefer ripening fruits or even corn 
when in milk, and then become troublesome. Belonging to this 
genus Allorhina are velvety-green and dull-brown beetles, an 
inch or more in length, which fly during the day with a buzzing 
sound somewhat like a bumble-bee, and usually close to the sur- 
face of the ground, except where they attack fruit. Yet I have 




Ligyrus rugiceps. — The beetle and its work. 



204 



AN ECONOMIC ENTOMOLOGY. 



seen hundreds of them flying about among half a dozen plum- 
trees, apparently injuring nothing but possibly themselves. 
Their larvae, however, feed on grass roots and are often trouble- 
some on lawns. They are quite large creatures and very hairy, 
with a fashion of travelHng on the back instead of the legs, when 
removed from their congenial soil. Heavy top-dressings of 
kainit and tobacco have proved about as effective as anything in 
dealing with these insects, though on a small scale the kerosene 
emulsion diluted ten times, and then washed into the soil by rain 
or frequent waterings, has proved effective. On any large area 



Fig. 194. 




AUorhma nitida.—a, larva ; b, pupa; c, adult ; d iog, structural details of larva. 

this process would probably be too expensive. The species is 
more common southward, and is more likely to become trouble- 
some on lawns, in parks, and in gardens than in the field. 

To this same group belongs the "Indian QoX-oma.,'' Euphoria 
iiida, which is one of the earliest of our Eastern beetles, flying 
in April or May over sandy or bare spots, close to the ground. 
At this time it is sometimes found on flowers, but remains only 
a few days. In early September a new brood appears, and this 
is occasionally troublesome, the beetles eating into ripe fruits or 
into corn. They have never yet appeared in such numbers, 
however, as to make remedial measures necessary. 

Taken as a whole, the LamelHcorns contain no directly bene- 
ficial insects, and the white-grub larvae are in many cases injurious 
when they feed on the roots of cultivated plants. Where a 
variety of cultivated crops follow each other, there is little chance 
for their excessive development, and frequent rotation is there- 
fore indicated, with as short a period in grass as may be. As 



THE INSECT WORLD. 



205 



the beetles in most cases appear in spring and oviposit late in 
May or in June, land bare at that time will probably escape. 
Fall sowing of crimson clover, to be turned under by the middle 
of May or before, will in some cases protect the land and act as a 
green manure if required ; or it may be allowed to remain until 
mature to make hay, and, if then ploughed and put into potatoes 
or some crop which the white-grubs do not attack, such as are 
then in the ground will be starved out. Where white-grubs are 
abundant, strawberries should not follow sod or other grass crop 
directly, and the beds should be kept clean, at least through the 
second year. Where the culprits are species of Lachnosterna, 
fall ploughing is indicated, since this will turn out the newly-formed 
beetles at an unseasonable period, and will cause their death in 
most cases. 

We now reach the great series of Phytophaga^ in which the 
tarsi are apparently four-jointed, the third joint deeply lobed. 
Two families belong here, — the Cerambycidcs, or long-horned 
beetles, and the ChrysomelidcB, or leaf-beetles. The ' ' long- 
horned ' ' beetles are so named from their usually well-developed, 
slender antennae, rarely shorter than the body, and often several 
times as long. They are usually more or less cylindrical, often 
with a vertical head, and always with well-developed mandibles. 

The larvae are wood-borers, using that term in a somewhat 
loose sense to include roots and the more solid parts of a few 
herbaceous plants, and are always cylindrical, the segments well 
marked, those immediately behind the head considerably enlarged, 
while anally they often taper quite abruptly. They are known as 
' ' round-headed ' ' borers to distinguish them from the ' ' flat- 
headed " larvae of the BuprestidcB, and the jaws, though rather 
small, are powerfully developed, fitted for cutting the hardest 
wood-fibre. In food habits the insects vary greatly, some attack- 
ing only dead or dying tissue, while others infest sound trees 
only. Perhaps in most cases they do best in somewhat weakened 
trees which their ravages soon kill entirely. 

Among our largest species are the Prio7iids in which the 
margin of the thorax is thin, sharp, and often toothed, and our 
most common species, extending over a large part of the United 
States, is Orthosonia bru7i7ieu?n, an oblong, somewhat flattened, 
brown species, from one and one-half to two inches or more in 



2o6 



AJV ECONOMIC ENTOMOLOGY. 



length. It is not economically important, unlike the "broad- 
necked Prionus," P. laticollis, whose larvae in blackberry are 
known as "giant root-borers." The beetle is black, robust, 
broader than usual, with a broad, toothed thorax, and from one 
to two inches in length. The larvae are immense, nearly three 
inches for a full-grown female, and they feed in the roots of a 



Fig. 195. 




The " giant root-borer," Prionus laticollis.— Larva, pupa, and adult. 

variety of trees and plants, including chestnut, oak, cherry, apple, 
grape, and blackberry. They require three years to reach 
maturity, and are sometimes decidedly troublesome. There is no 
way of reaching the larvae except to dig them out, and in black- 
berry fields the sudden wilting of part or all of a hill indicates 
almost infallibly the presence ol one or more, which should then 
be found and destroyed at once. Grape and apple stand the 
injury better, "but when a tree becomes badly infested nothing 
remains but to take it out and burn it. Even large trees are 



THE INSECT WORLD. 



207 




Phymatodes amcenus : pupa and adult. 



sometimes killed, an old cherry-tree, fully eighteen inches in 
trunk diameter, which died rather suddenly, having the roots 
absolutely riddled in every direction by a dozen or more of these 
immense creatures. 

The species of Phymatodes are much smaller, a little flattened, 
with an oval thorax and a tendency to blue and yellow colors. 
The larvae feed only in dead or 
dying wood : P. amoenus, a bright 
blue species w4th yellow thorax, 
attacking dead shoots of grape, 
while P. varius and P. variabilis 
live under the bark of oak cord- 
wood. The beetles appear in 
spring and lay their eggs in 
dying wood or in wood cut 
during the winter, often in such 
numbers that the bark is com- 
pletely loosened by the larvae and will, next spring, slip off in 
its entirety. They are hence called "bark-slippers" by wood- 
men. In the Southern States they infest tan-bark, sometimes 
injuring it considerably. Cutting the tree? during the summer, 
after the beetles have disappeared, or very early in fall will put 
the bark and wood in such condition that it will not be attractive 
the season next following. 

The species of Elaphidion are narrow, brown beetles, covered 
with whitish, somewhat mot- 
tled pubescence, and have long 
and rather stout antennae. 
They are known as ' ' oak- 
pruners," because the larvae 
of several species bore into 
twigs and branches of oak and, 
when nearly full grown, girdle 
them from the inside, so that 
the first high wind of early 
winter breaks them off, carry- 
ing the larvae to the ground. 
Transformation is completed in the June or July following. Often, 
during late summer, the wilting of a twig or small branch indi- 



FlG 




The oak-pruner, Elaphidion parallelum, 
—a, larva ; b, pupa in its burrow ; c, beetle ; 
kk, cut ends of the twig ; d to i, structural 
details. 



2o8 



^^v iLL.ui\UMIC ENTOMOLOGY. 



cates the presence of such a larva. Apple-trees are sometimes 
attacked, and the best measure for general adoption is the sys- 
tematic gathering and burning of all fallen twigs and branches 
during the winter. The insects are not confined to terminal 
branches only, but sometimes attack the trunks of young shoots 
or trees after a fire has been over the ground and scorched them, 
and in such cases the larvae make no effort to girdle. 

In the genus Cylle^ie we have moderate-sized species that 
are dark velvety brown or blackish, with bright golden-yellow 
bands. Of these, C. pidus infests hickory not uncommonly, 
and appears in spring, while C. robmicB infests the locust, and 
appears in fall. This latter is a serious pest, and makes growing 
locusts simply impossible in many localities. As soon as a tree 
Fig 198 attains a moderate size it is riddled with the 

large holes made by the larvae, and leads but 
a sickly life for a few years thereafter, event- 
ually dying down to the ground. The 
beetles themselves frequent the flowers of 
golden-rr^^, and may be collected there in 
greai i bers, the females resorting to the 
locusts ly when ready to oviposit. An 
allied, larger and prettier, species, Pla- 
^ic '^ speciosus, bores into maple, but 

Plagtonotus spectosus. r 

IS usually somewhat rare and has not proved 
injurious until very recently in some parts of New Hampshire, 
where certain shade-trees suffered. 

We sometimes find a small larva belonging to this series boring 
into the branches and smaller shoots of currant- 
FiG. 199. bushes, and early in spring these change to a 
small, brown, somewhat flattened beetle, rarely 
exceeding one-quarter of an inch in length, 
clothed with white hair grouped to form two 
white spots towards the end of the wing-covers. 
This is the Psenocorus supernotatus, which is 

American cur- , ^ 

rant-borer, Pse?zo- occasionally abundant enough to be troublesome. 
corussupernotatus, j^eld in chcck by closc pruning during 

enlarged. . . , 1 1 r • 

the wmter, the cuttmgs to be burnt before sprmg 
opens to destroy the contained larvae. 

In late spring or early summer some of the terminal shoots 





Fig. 20I. 




Work of the locust-borer, Cyllene robinics. 



THE INSECT WORLD. 



209 



of apple-trees may suddenly wilt and the leaves become brown 
and dry, the fruit, if any, dropping to the ground. These 
wilted shoots will be found hollowed out, and the culprit is the 
larva of another litde brown longicorn, about one-quarter of an 
inch in length, quite robust and cylindrical, the wing-covers a 
little mottled with rather long, pale hair. It is a species of 
Eupogonius which has not figured much in economic literature, 
because its injuries rarely amount to more than a light summer 
pruning. On smaller trees the infested shoots can be cut and 
destroyed and on larger trees careful winter pruning is indicated. 

A well-known orchard pest is the round-headed apple-borer, 
the larva of the Saperda Candida. It attacks quince in prefer- 



FiG. 200. 




Round-head apple-borer, Saperda Candida.— a, larva ; b, pupa ; adult. 



ence even to apple, but is more rarely found in pear. The 
beetle appears late in June or early in July, depending somewhat 
upon latitude, and lays its eggs on the trunk, as near to the surface 
of the ground as possible, under a loose bark-scale or in a little 
hole gnawed by its mandibles. The larva lives for a year in the sap 
wood, then bores into the trunk, up or down, sometimes some 
distance below the surface, and in the spring of the third year 
changes to a beetle. Trees of quite large size are killed in a 
- very few years, and for some time before are sickly and do not 
properly mature a crop of fruit. All sorts of remedies and 
devices have been proposed, cutting out the larvae being the one 
most relied upon even yet. This means, in many cases, making 
an additional large wound in the tree, and sometimes the remedy 
is worse than the disease. The best method of protection, and 

14 



2IO 



AJV ECONOMIC ENTOMOLOGY. 



Fig. 203. 



this applies as well to other species infesting tree-trunks, — e.g.^ 
the locust-borer, — is mechanical, the trunk being covered or 
coated by some material impenetrable, repellent, or destructive 
of or to the adults, thus preventing oviposition. The most 
satisfactory and lasting measure, all things considered, is cover- 
ing the lower portion of the trunk with wire mosquito-netting, 
tying at the top and hilling up against it at the bottom. The 
netting should extend at least two feet up the trunk and above 
that a coat of whitewash should be maintained during the danger 
season. Other measures, equally useful here, have been already 
referred to when speaking of the ' ' flat-headed borers. ' ' 

In the genus Oncideres we find a curious and interesting egg- 
laying habit : the beetle lays an egg in a twig or branch, and 
then girdles it at a little distance below, eating 
so far through that a high wind brings it down. 
The twig wilts at once and the wood is then in 
the exact condition desired by the larva, which 
undergoes its transformations undisturbed by 
growth or undesired moisture. Sometimes 
shade-trees are attacked ; but merely gathering 
and burning the fallen wood keeps the insects 
in check. 

There are many other longicorns in our fauna, 
nearly six hundred species being listed in the 
catalogues, and many are beautiful as well as 
interesting. The few species referred to here 
do not even illustrate all the different types, 
but are all that are sufficiently injurious to be 
referred to at any length. Wooded regions 
furnish the greatest variety of species, and all 
portions of the trees furnish support for their 
larvae. 

The family ChrysomelidcB, or leaf-beedes, contains species 
that, in the main, feed upon leaf- tissue in the larval as well as 
adult stages, and many of them attack cultivated crops. The 
beetles may be distinguished by the tarsal structure already 
described, by their usually moderate or small size, short antennae 
which are not situated on frontal prominences, and by their 
usually margined, not cylindrical prothorax. The larvae vary 




The "twig-gird- 
ler," Oncideres cin- 
gulatus. — a, beetle 
at work ; b, egg- 
puncture ; c, gird- 
ling done by beetle ; 

egg. 



THE INSECT WORLD. 



211 



Fig. 204. 



considerably in form and habit, but are often more or less viscid, 
and are then termed slugs. 

Belonging to the genus Lema is a little series of species, several 
of which feed upon the potato, and of these the best known is 
the Lema j-li7ieata, or " 3-lined potato-beetle." It is yellow in 
color, the head and thorax much narrower than the body, and 
the wing-covers have three broad, black stripes. It is rarely 
abundant now-a-days, though at one time a somewhat important 
species, and it may be easily controlled by the use of the arsenites. 
In fact it is the treatment adopted for the better-known ' ' Colo- 
rado ' ' beetle that has in a large measure exterminated the Lema. 

Somewhat allied in form are two species of Crioceris^ both 
feeding on asparagus, and both introductions from Europe. The 
common "asparagus-beetle," C. asparagi, is about one-fourth 
of an inch in length, the wing-covers black with red or yellow 
markings, the thorax red with black dots. It hibernates as an 
adult, and appears early in spring, eating into the asparagus 
shoots and laying its eggs upon them. 
These eggs are black and quite long, cylin- 
drical, set on end so as to project from the 
shoots in every direction. The larvae hatch 
soon thereafter, and are slimy, greenish 
slugs, with black dottings, a blackish head, 
and black legs. They often do great in- 
jury, particularly on young plants. On 
beds where cutting is done, a few shoots 
should be allowed to grow as traps during 
the cutting season, and on these the ma- 
jority of beetles will oviposit. In a week 
they should be cut and destroyed, other 
shoots being allowed to take their place, to 
be similarly treated thereafter. If this prac- 
tice is kept up for a month, no injury need 
be anticipated later on, as the species will 
be too much reduced in numbers to be- 
come troublesome. No volunteer aspara- 
gus should be permitted, as otherwise the 
there. In young beds the beetles cannot 




Asparagus-beetle, Crio- 
ceris asparagi: larva, 
adult, and shoot with eggs. 

insects will multiply 
be checked, because 



spraying the feathery leaves is impracticable, but after the larvae 



212 



AJV ECONOMIC ENTOMOLOGY. 



develop, they may be readily brushed off with a stick in the 
middle of a hot day and few of them ever get back, a short 
period on the hot soil proving fatal. The work can be done 
very rapidly, and is needed two or three times only to secure 
entire protection. Where a field of old shoots becomes badly 
infested by larvae, much benefit may be derived by a thorough 
dusting with fresh, dry slacked lime early in the morning while 
the plants are yet a little moist with dew. The lime, if properly 
prepared, is sufficiently caustic to burn holes into and kill the 
slimy larvae. As new specimens are constantly hatching, this 
dusting must be done several times at short intervals, but is sure 
to prove effective if thoroughly carried out. 

The " 1 2-spotted asparagus beetle," C. i2-pU7ictatus, is some- 
what larger and more robust, uniformly reddish in color, with 
twelve black spots on the wing-covers. It is as yet less common 
than its ally and not so widely distributed, but may be treated in 
much the same way. 

The species of Fidia are robust, rather long-legged creatures, 
covered with short hair, giving them a more or less marked gray 
appearance, and they feed largely upon grape. Fidia viticida 
has proved locally injurious in Ohio, and, as the species occurs 
over a large portion of our country, it may break out anywhere 
at almost any time. The beetle feeds upon the foliage, eating 
irregular holes on the upper surface in June. Eggs are laid on 
the trunk of the vine or on the branches in any available crevice, 
and the larvae drop to the ground when hatched, making their 
way beneath it as best they may, to the rootlets upon which they 
feed. Remedial measures have not as yet proved very satisfac- 
tory, but spraying with a strong arsenical mixture, using lime to 
avoid burning the foliage, will kill many of the beetles. Culti- 
vating the ground so as to have a loose powdery top soil without 
crevices leading to the roots, which should also be covered as 
deeply as possible, will prevent many of the larvae from reaching 
their feeding place. 

Strawberry plants are sometimes injured by whitish larv^ 
feeding upon the roots, and from these are produced small, shin- 
ing, black or brownish beetles belonging to Paria ate7'rh7ia, or 
certain allied species popularly known as "strawberry root- 
borers." The best measures here are clean culture and frequent 



THE INSECT WORLD. 



213 



change of location for the strawbern' beds. The insects are 
rarely troublesome in the Eastern, but often injurious in the 
Central States. Old beds should be ploughed out and destroyed 
as soon as they have been picked, and when new beds are set out 
care should be used in selecting plants free from insect attack. 
Where a two-year picking rotation is used and the old plants are 
immediately destroyed, the species are not able to increase ex- 
cessively. The arsenites may be satisfactorily used to kill the 



Fig. 205. 




Grape-root-worm, Fidia viticida.—A, adult; B, pupa ; C, larva; the other letters refer 
to details of larval structure. 

adults when they are noticed feeding upon the foUage. Using 
commercial fertilizers instead of barn-yard manure is also to be 
recommended. 

Perhaps the best-known species of this family is the ' ' potato- 
bug," or "potato-beetle," or " lo-Hned beetle," or "Colorado 
potato-beetle," Doryphora lo-lineata. No description of this 
insect is necessary, the figures serving to illustrate all its stages 
sufficiently well. The insects winter underground as adults or 
pupae, and the beetles emerge early in spring, attacking the 
young plants as soon as they show above ground, and laying 
eggs for the livid-reddish larvae. About midsummer these have 
matured a second brood of beetles, and a second brood of larvae 



214 



AJV ECONOMIC ENTOMOLOGY. 



follows shortly thereafter, resulting in a fall supply of beetles, 
which, as a rule, hibernate. Sometimes a third partial brood of 
larvae reaches the pupal state, and hibernates in that condition. 
The arsenites are well-known and approved remedies, used at the 
rate of one pound in from seventy-five to one hundred gallons 
of water, and several machines especially intended for spraying 
potato-fields are on the market. The insect maintains itself 
unchecked, because, while active war is waged against the first 



Fig. 206. 




The Colorado potato-beetle, Doryphora lo-lineata. — a, a, egg patches ; b, b, b, larvae in 
different stages of growth ; c, pupa; rf, beetle; e, its elytra enlarged. 



brood, little attention is paid to the second, and this is usually 
allowed to mature and provide for a new crop the year following. 
Spraying should be done first as soon as the beetles begin feed- 
ing, to prevent oviposition if possible ; it should be done a sec- 
ond time when larvae appear generally, and it should be done as 
often thereafter as beetles or larvae are noticed infesting the 
plants. 

The species of Diabrotica are rather slender, with long an- 
tennae ; of a green or yellow color, with black spots or stripes. 
The adults feed on leaves, flowers, or pollen, but the larvae, which 
are white and slender, usually feed in the roots or stems of plants. 
One of our most common forms, D. vittata, is known as ' ' the 
striped cucumber-beetle," and is yellow with black stripes on the 



THE INSECT WORLD. 



215 



wing-covers. It feeds on all kinds of cucurbit vines, and on 
many other plants as well, doing injury by eating into the stem 
of the young shoots at or below the surface, where it has a ten- 
dency to hide during the middle of the day. The larvae live in 
the main roots underground, making short galleries, which, if 
numerous, weaken or even kill the plant. The beetles winter as 
adults. A free use of tobacco dust around young vines or other 
injured plants is usually protective, though in some localities the 
farmers resort to ' ' driving. ' ' They do this before the middle of 
the day, sowing air-slacked lime with the wind, and this seems 
to be sufficiently offensive to the insects to induce them to leave 
for fields to the leeward, where they, of course, become doubly 
injurious unless also driven off. Planting an excess of seed to 
distribute the injury is a common practice, and so is starting the 
plants in baskets and setting them out when well established and 
able to resist injury. Melon and other cucurbit vines should 
always be plowed out, raked up, and destroyed as soon as pos- 
sible after the crop is off, to destroy any larvae that may be then 
in the roots. 

An allied and equally common species, feeding as an adult 
upon a great variety of plants, is the D. i2-pimctata, or "12- 
spotted Diabrotica." This is somewhat larger than the preced- 
ing, with a more oval body, and has twelve black spots on the 
greenish-yellow wing- covers. The larva feeds on the roots of a 
variety of plants and becomes injurious to corn in the Southern 
States. There are two broods, and the beetles winter in the 
adult stage. No direct remedy is known, but good cultivation 
and a liberal application of stimulating fertilizers is advisable to 
enable the corn-plant to resist and outgrow attack. Clean cul- 
ture is the greatest essential, and this of itself will do much to 
reduce injury. 

The ' ' corn-root Diabrotica' ' of the Western and Central 
States is of a uniform, pale-green color, named D. longicornis, 
from its long antennae, and its larva has proved a serious pest to 
corn. The complete life history of the insect is known, and as it 
winters in the egg state in corn-fields, simple rotation is all that 
is necessary to destroy the species. It can never become injuri- 
ous unless corn follows corn year after year, and even a single 
year without corn serves to completely rid a field of the pest. 



Fig. 209. 




Fig. 207, Lema trilineata. Fig. 20S, a. a, larvae ; c. pupa ; d, eggs of Lema trilmeata. 
Fig. 209, Diabrotica 12-punctata: a, egg; b, larva; c, injury in corn-stalk; d, pupa; 
^, beetle. Fig. 210, Diabrotica longicoryiis : a, adult; 5, pupa; c, larva; d, same in its 
case. Fig. 211, Diabrotica vittata. Fig. 212, larva of same. Fig. 213, its pupa. 
216 



THE INSECT WORLD. 



217 



The genus Galeruca contains a series of rather small, oblong 
species, mostly dirty clay-yellow in color, and more or less black 
marked or spotted. Of these none is more troublesome than the 
" elm-leaf beetle, " Galeruca xanthomelcsna, which is another of 
our undesirable importations from Europe. It is rather greenish 
yellow when fresh, with two black stripes on the wing-covers. 
It hibernates as a beetle wherever it can find shelter, and attacks 
the leaves of elms in spring as soon as they are well grown, 
eating irregular round holes, so they soon look as if loads of 
shot had been fired through them in every direction. The yel- 
low, bottle-shaped eggs are laid in double rows on the under 
sides of the leaves, and from them hatch the yellow, black-spotted 
larvae, covered with little bristly tufts of hair. In the northern 
part of its range, including the red shale of New Jersey, a single 
brood is normal, but south of this, and including an extension 
into Long Island, the insect has two broods annually, and at 
Washington or further south may have three or even more. As 
against these insects the arsenites are effective, and the trees 
should be sprayed, preferably with the arsenate of lead, just as 
soon as the beetles begin feeding. The object is to destroy as 
many of the hibernating forms as possible, and to prevent egg- 
laying in large part. A second spraying should be given when 
the eggs begin hatching, to destroy the young larvae, and in 
serious cases a third spraying a week or ten days thereafter will 
be beneficial. When the larvae are full grown they descend the 
trunk to the ground, where they change to bright-yellow pupae 
among the grass or rubbish on the surface. Here they may be 
destroyed by hot water, kerosene, strong soap-suds, lime, or 
other suitable substances, and the second brood, where such 
occurs, may thus be materially lessened. Where there are two 
broods or more, repeated sprayings will be necessary, extending 
throughout the summer. If these methods are generally adopted 
the insect can be satisfactorily controlled. Protecting a few trees 
- only among many that are neglected will always be difficult and 
can be at best only partly successful.^ 

* For detailed information concerning the treatment of trees in cities 
or towns, or on a large scale, the publications of the United States De- 
partment of Agriculture and of the New Jersey Experiment Station 
should be consulted. 



2l8 



AJV ECONOMIC ENTOMOLOGY. 




THE INSECT WORLD. 



219 



Distinct from all the forms hitherto mentioned are the ' ' flea- 
beetles, ' ' so called because of their greatly enlarged hind femora, 
giving them the power of making sudden leaps ending in flight. 
We have many species, and some of them are decidedly injurious 
and troublesome to deal with. 

The grape flea-beetle is a well-known species called Haltica 
chalybea^ from its steel-blue color, and it feeds both as adult and 
larva on the leaves of the grape. The larvae are blackish and 
slender, slug-like and somewhat viscid, feeding in company 
during a great part of their growth. They are easily controlled 
by any stomach poison, and the Bordeaux mixture, applied as a 
fungicide, seems to be eflective in keeping them in check. 

The genera Crepidodei^a and Epitrix contain a number of 
small species, among which the "cucumber flea-beetle," or 
"potato-flea," Epitrix cuciwieris, easily ranks first. As a small 
black beetle, it eats little round holes into the leaves of potato, 
tomato, egg-plant, and a variety of other solanaceous plants, as 
well as into those of melon, cucumber, and other cucurbitaceous 
vines. Potatoes seem rather the favorite food, and where the 
beetles and their little holes are numerous the leaves turn brown 
and die, checking the growth of the plant, and hence of the 
crop. The larvae are leaf- and stem-miners, but do little or no 
damage. Usually Paris-green and London-purple are satisfac- 
tory remedies, and it has been observed that the Bordeaux mix- 
ture acts as a deterrent when liberally used, serving thus the 
double purpose of checking insect injury and plant disease. 
Tobacco is also a very satisfactory material used as a decoc- 
tion, but is scarcely economical except on a small scale or in 
gardens. 

The "sweet-potato flea," Chcstocnema conjims, is an inter- 
esting, if troublesome, small, bronzed beetle, attacking the leaves 
of the young plants just after they have been set out, and eating 
little channels along the veins, finally making the net-work so 
complete that the leaves shrivel and dry. If the vines get a fair 
start, they outgrow the injury very rapidly, but cold, wet weather, 
by retarding growth, sometimes enables the insects to kill them. 
Dipping the plants before they are set out in the arsenate of lead 
mixture, at the rate of fifteen ounces to fifty gallons of water, will 
prove a satisfactory protection without danger of injury to the 



THE INSECT WORLD. 



221 



plants. Or they may be thoroughly sprayed with the Bordeaux 
mixture immediately after being set out. 

Of somewhat larger size and more slender, graceful form are 
the species of Systena, and of these, kS. blanda, the ' ' pale-striped 
flea-beetle," has become best known by reason of its injury on a 
great variety of plants, including sugar-beets. As with the other 
" fleas" it is injurious in the beetle stage only, and, as a rule, in 
early summer on young plants. I have seen it ruin an entire 
field of carrots, and have found it on melons, potatoes, beets, and 
pig-weed in equal abundance. Its life history has not been pub- 
lished, but its larva is said to feed upon corn-roots. This is cer- 
tainly not universally true, and its native food-plant in the early 
stages remains to be ascertained. As with other leaf-feeding 
forms, we are referred to the arsenites; or, as a means of protection 
only, to air-slacked lime, which will drive the beetles to wild 
plants, leaving the lime-dusted crop free. 

In the genus Phyllotreta we find another series of small species 
not exceeding one-eighth of an inch in length, ordinarily black in 
color, with yellow stripes or 

spots on the wing-covers. The Fig. 221. 

most common species in the 
East is the ' ' wavy-striped flea- 
beetle," P. vittata, in which 
there is a distinct yellow stripe 
through the middle of each ely- 
tron. The adults feed upon the 
leaves of cabbage, radish, mus- 
tard, and others of the cruciferse, 
while the larvae live as miners 
in the tissues of the same plants. 
In dealing with this species 
the important points are clean 
culture and keeping down all 
cruciferous weeds. If in addi- 
tion all crop remnants are promptly gathered and destroyed, no 
serious danger need be apprehended. 

Following the flea-beetles is a series of very curious, somewhat 
wedge-shaped insects, the Hispidcs, in which the antennae are 
thickened, and the elytra, or wing-covers, broaden to the tip, 




Striped flea-beetle, Phyllotreta vittata.- 
a, larva ; b, adult. 



222 



A.V ECONOMIC ENTOMOLOGY. 



where they are rather abruptly terminated. The larvae are leaf- 
miners, and perhaps the most common species is the Odojitota 
dorsalis, or locust-beetle, which occurs abundantly on the leaves 
in early summer, and is orange in color, with a broad black 
stripe on the centre of each elytron. The eggs are covered with 
a little mass of excrement, and are laid singly, few leaves con- 
taining more than two or three. Not much real injury is done 
by any of the species, and the suggestion that the adults feed 
exposed and succumb readily to the arsenites is all that is neces- 
sary on the subject of remedies. 

The adult Cassidce are called "tortoise-beetles," or, by the 
sweet-potato grower, ' ' golden bugs. ' ' They are characterized 
by their broad, almost quadrate form, flat under and convex 
upper side, and by the moTe or less metallic-yellow or golden 
color of the elytra and upper surface generally. Most of the 
species feed upon Convolvulus^ to which natural family the sweet- 
potato belongs, and the 
latter is about the only cul- 
tivated crop suffering from 
the attacks of insects of this 
series. The beetles hiber- 
nate and appear in the sweet- 
potato fields as soon as the 
crop is set out, eating irreg- 
ular holes in the leaves, and 
laying their eggs, encased in 
a mass of excrement, on the 
under surface. The larvae 
are known as "peddlers," 
because they have piled 
upon a pair of anal forks all 
the cast skins and a part of 
their excrement, forming a 
sort of shelter, umbrella, or 
"pack," to which latter 
resemblance they owe the 
common name. The most abundant form is the Cassida bivittata, 
or "two-striped tortoise-beetle," so named from the two black 
stripes on each wing-cover. Following closely is the Coptocyda 




Coptocycla aurichaicea. — a, larvse, or ped- 
dlers, with their packs; b, larva with pack 
removed ; c, pupa. 



THE INSECT WORLD. 



223 



miJ'ichalcea, so named because of its resemblance to a drop of 
molten gold. The injury is done by these species just after the 
plants are set out and before they get a start. Where the season 
is unfavorable to rapid growth, some plants may be killed, but 
under ordinary conditions they are soon out of danger. Good 
practice is to set only large, weU-developed plants, or to dip 
everything before setting out in the arsenate of lead mixture 
recommended against the flea-beetles. Finally, it has been found 
that chickens are fond of the insects in all stages, and by turning 
loose a sufficient number in the fields after the plants have been 
set out practical exemption is secured. 

The bean- and pea-weevils constitute a little family by them- 
selves under the term BruchidcB. They agree with the leaf- 
beetles in general structure, but 
have a small head, prolonged into -^2- 
a blunt snout, a very obese abdo- 
men, exposed at the tip by the 
short, square wing-covers, and 
much enlarged hind legs, which 
are not used for leaping. They 
are always small and usually more 
or less ashen-gray in color, covered 

with whitish hair or scales, which Bean-weevil, Bruckus fabce much 

enlarged; 5, an infested bean. 

form variably evident markings on 

the wing-covers. The beetles are often found in dried seeds of 
leguminous plants, — peas, beans, lentils, or the like, — and are 
sometimics seriously injurious in the stored product, lessening 
also or destroying the germinating power. The beetles come 
out normally in the spring, and after pairing the females lay 
their eggs in the young pods of the plants affected by them. 
The larvae work their way into the forming seed and grow very 
slowly, the species varying somewhat in the details of their life 
history. Our only method of controUing the insects is in the 
stored product, or seed, and here by means of bisulphide of car- 
bon we can kill lan^ae as well as adult beetles, in any moderately 
tight receptacle. The rule should be, gather the entire crop and 
allow nothing to remain in the field ; plant only sound seed, and 
never under any circumstances throw away weevilly" peas, 
beans, lentils, etc. They should always be burnt, or otherwise 




224 



AJV ECONOMIC ENTOMOLOGY. 



completely destroyed. Wild as well as cultivated plants are 
infested, though we do not know that insects infesting our garden 
varieties are carried over by other wild species. 

Fig. 224. 




Fig 



'Pq3.--wqqv\\, Brzichus pisi.—c, larva; d, pupa; i^, adult ; all enlarged. 

We now reach the series Heteroniera, or beetles in which the 
fore and middle tarsi have five joints, while the posterior are 
four-jointed only. We have rather a large number of families, 
many with a few species only, and as a whole they are feeders 
in or on decaying or dry vegetable tissue, whether herbaceous, 
woody, or fungoid in character. There are exceptions, of course, 
but that is the rule. 

The TenebriojiidcE, or "darkling-beetles," contain species 
ranging from quite small to very large, found under all sorts of 
conditions, but most frequently beneath 
bark of trees, on fungi, or under stones, 
among dry vegetable matter. There is 
no uniformity in appearance, but in most 
instances the antennae are more or less 
moniliform, or bead-like. The majority 
of our species are Western, occurring in 
their greatest variety in the Rocky 
Mountain region, but none, so far as I 
know, trouble green vegetation. The 
typical genus Tejiebrio contains black or 
brownish, somewhat flattened species, 
with a square thorax and deeply ridged 
wing-covers. The larvae are known as "meal-worms," and feed 
upon grain or meal remnants in barn, stable, or other sheltered 




The meal-worm, Tenebrio 
molitor.—a, larva ; b, pupa; 
c, adult ; d io h, structural 
details. 



THE INSECT WORLD. 225 

Spots. They are often bred by bird-fanciers in large numbers, 
and only need plenty of food to multiply rapidly. They rarely 
do serious injury, but are not pleasant to have around, and may 
be easily controlled by cleanliness, supplemented in extreme 
cases with bisulphide of carbon. A few other small, brown 
forms, among which the species of Triboliu^n may be mentioned, 
occur under Uke circumstances, but are amenable to the same 
treatment. 

Fig. 226. 




TriboHum confusum.—a, adult; b, larva; c, pupa; e, head, with antenna; /, same of 

T. ferrugineum. 

Perhaps the most interesting, and economically the most im- 
portant of this series, are the "blister-beetles," or MeloidcB. 
The name ' ' blister-beetles' ' is from a peculiar property possessed 
by them of raising blisters on the human skin. This is due to a 
substance called " cantharidin," found in the juices of all the 
species to a greater or less extent. The species generally used 
in medicine comes from Spain, hence the insects are also known 
as "Spanish flies." The beetles are rather soft-bodied, with 
broad heads, the antennae often knotted in the males, the thorax 
narrow and cylindrical, the wing-covers extending w^ell down the 
sides. Some of the species are brightly colored and banded, 
occasionally metalHc bronze or coppery, and all of them are leaf- 
feeders. Among the common eastern species several attack 
potatoes, and of these a yellow and black-striped form, Epicauta 
vittata, is known as the "old-fashioned potato-bug." Asters 

15 



Fig. 227. 




Meloid., or - blister-beetles. '-Fi^ IS..^^^ ^S.^ 
Epicauta vittata: a. second larN a : P^^ co^ra3.\^ pi- grasshopper egg-pod 

« and b, true pupa of same, from s de ^"^^^'^°"^oid l1ir% a ' e\ rcarabidoid larva. Fig, 
a few eggs from same ; ^..^mngulm ,^ %fjauta cln^^^^^^^ 233, a, Macrobasts um- 



231, aduft Epicauta vittata. Fig, 
color; b, Epicauta pennsylvamca. 

226 



THE INSECT WORLD. 



227 



and other flowers are injured by a black species with gray- edged 
elytra, Epicauta cinerea, and among field-crops beets are, after 
potatoes, the chief sufiferers. The beetles appear quite suddenly 
in large numbers, and some species disappear almost as quickly, 
while others linger several days. A uniformly black form, 
Epicauta pen7isylvanica, is often found in considerable numbers 
on the flowers of the golden-rod in August and September, while 
a uniformly gray species, Macrobasis unicolor. is common on the 
false indigo. 

The life history is interesting, and the species may be divided 
into two series, those living in the nests of burrowing bees and 
those living in grasshopper eggs. In the first series the eggs are 
laid on flowers, and from each hatches an active little creature 
with long legs, prominent jaws, and large head, which is known 
as a " triungulin." It runs about the flowers until the proper 
kind of bee comes along, gains a foothold on this, and, buried 
among the hairy clothing, allows itself to be transported to the 
bee nest. There it quits its unconscious host, makes its way 
into one of the completed cells, devours first the egg or young 
larva, and then completes its own transformations, feeding upon 
the stores now without another owner. This type is only 
indirectly of economic interest, but is rather injurious than 
otherwise. 

In the second series the egg is laid either on a plant or on 
the ground, but in either case a triungulin similar to that above 
described results, and this has the power of existing without food 
for several days, while hunting for a grasshopper egg-pod. When 
such a one is found its wanderings are over, and it begins feed- 
ing at once. When it moults its large head and long legs disap- 
pear, and it resembles a Carabid larva, with ovate body, small 
head and jaws, and short legs; it is now in the " carabidoid" 
stage. Again it moults, and now the resemblance is to a 
small "white grub," for which reason this has been termed 
* the " scarabidoid" stage. When all the grasshopper eggs are 
devoured, our larva is full grown, ceases feeding, and shrinks 
into its own hardened skin, forming a coarctate stage, or 
pseudopupa, in which it winters. In spring it emerges from this 
covering, is active a short time without feeding, and then enters 
the true pupal stage, in which it resembles other Coleoptera. In 



228 



AN ECONOMIC ENTOMOLOGY. 



this stage it remains until the proper conditions occur, and then 
joins its companions in a seemingly concerted movement to arise 
and assume the beetle stage. This uniformity of development 
explains the sudden appearance of the insects in large numbers, 
and their power to cause mischief is derived from it, since the 
farmer does not often realize the nature of the invasion until con- 
siderable injury has been done. In the larval stage they are 
beneficial, in so far as they feed upon the eggs of grasshoppers, 
but it is questionable whether this benefit overbalances the dam- 
age they do as adults, and I never hesitate to advise prompt 
measures for their destruction. The best of these is a thorough 
application of one of the arsenites as soon as the insects appear, 
adding milk of lime to make the poison stick better and to dis- 
courage feeding. In small patches the beetles can be gathered 
in pans early in the day, or they may be driven to a layer of 
straw, the latter to be set on fire when the insects become en- 
tangled among it. The last is the least desirable of the measures, 
though under some circumstances very effective. In all cases, 
promptness is essential. 

The Rhynchophora, or "snout-beetles," are separated into a 
number of families which need not be particularly described here, 
but all agree in having a more or less evidently produced beak 
or snout, at the end of which the small mouth parts are situated. 
The terms " curcuHos" and "weevils," in addition to that above 
given, are rather indiscriminately applied to species of this series. 
All the snout-beetles are vegetable feeders in both larval and 
adult stages, and, therefore, more or less injurious. Many of the 
larvae are internal feeders, and, therefore, white or yellowish, 
usually with short, bristly hair, a brown head, and no feet. As 
a rule, they are somewhat curved and terminate rather bluntly, a 
little like "white grubs," but without the peculiar, large, ter- 
minal segment. It will be necessary to restrict our mention to 
the most troublesome forms, and the first of these, in systematic 
order, is " Fuller's rose-beetle," Aramigus fulleri. 

This beetle, which has a short, obtuse snout, and is of a dark, 
smoky- brown color, lays its eggs in little masses under any sort 
of shelter on rose-bushes, and the resulting white, grub-like 
larvae feed on the tender roots of the plants. The insect is, 
essentially, a green-house pest, and often weakens the plants, so 



THE INSECT WORLD. 



229 



as to render unprofitable if it does not kill them. The beetles 
are long-lived, and hide during the day on the under side of the 
leaves on which they feed. Hence, collecting and destroying 
them is the most satisfactory remedy, while the use of a tobacco 
extract on the ground will act both as a fertilizer and to destroy 
the subterranean larvae. 

The clover-leaf beetle, Phytonomus pundatus, is another quite 
large species, dull brown in color, with indefinitely striped wing- 



FiG. 234. 




Clover-leaf beetle, Phytonomus punctatus. — a, egg; b, b, larvae feeding; c, very young 
larva;/, cocoon, its net-like character shown at^/ h, pupa; i, beetle, on clover-stalk ; 
k, same, enlarged ; other letters refer to structural details. 

covers, and a short, stout beak. The larva is green, its form well 
shown in the figure, and it feeds chiefly at night, eating irregular 
holes in the leaves. When full grown it forms a peculiar net-like 
cocoon at or a little beneath the surface of the ground and 
pupates, becoming adult a few days thereafter. The insects 
hibernate in the larval stage, and their injury becomes manifest 



230 



A A' ECONOMIC ENTOMOLOGY. 




Diseased 
larva of clover- 
leaf beetle. 



quite early in the season, often threatening entire destruction of 
the crop when they are nearly full grown. Fortunately, nature 
has provided a check for this insect in a fungous disease which in 
most localities carries off the larvae annuallv, iust 
Fig. 235. before they mature, leaving only a comparatively 
small proportion to perpetuate the species. As 
this disease seems to occur in seasons of all kinds, 
and irrespective of climatic conditions, it can be 
easily introduced into any locality in which the 
insects become destructive. Affected lar\-ae curl 
themselves round a spear of grass or on the edge 
of a leaf and die, first swelling somewhat and 
becoming gray in color ; then they collapse and 
become black, eventually forming a small, dried, 
black mass, utterly indistinguishable in character. 
The ' ' white-pine weevil, ' ' Pissodes strobi, is one of the most 
serious enemies to that tree, and in the more northern States 
attacks the leading shoots, in young trees spoiling their shape 
completely. The insect has been studied, and a full account 

is given in the Fifth Report of 
the United States Entomological 
Commission, dealing with forest 
insects, but no satisfactory reme- 
dial measures are proposed. In 
parks or gardens small orna- 
mental trees can probably be 
protected by keeping the leading 
shoots sprayed during the spring 
with a carbolated soap-wash, to 
which Paris green has been 
added at the rate of one pound in one hundred and fifty gallons 
of water. Other infested shoots should be gathered and burnt. 
The report above cited is so full on the subject of forest insects 
belonging to this series that only those infesting cultivated crops 
need be discussed here. 

Early in the season we find on the leaves and stems of rhubarb 
a rather long, cylindrical weevil, Lixus concavus, with a short 
heavy snout, entirely covered by an easily rubbed off, rusty 
powder. It is also remarkable for its exceedingly firm texture. 




White-pine weevil, Pissodes strobi 
its larva ; b, its pupa. 



THE INSECT WORLD. 



231 



Fig. 237. 




making it difficult to pierce with any ordinary pin. It bores 
little holes in the leaf and flower stems of the plant, laying an 
egg in each, from which hatches in 
due time a white, grub-like lar^^a, 
which feeds in the plant tissue. 
Where the leaves are regularly cut 
for market, little trouble is experi- 
enced. All old leaves not needed 
by the plant should be removed and 
destroyed, so that after midsummer 
none of the early leaves should re- 
main on the plants. If this practice 
is constantly carried out no injury 
need be apprehended. The natural 
food-plant is said to be dock. 

In the genus Antho7iomus small 
species predominate, and the colors 
are modest, but their powers of in- 
jury are by no means in proportion 
to their size. One of the most trou- 
blesome is the "strawberry-weevil," 
A, signatiis, which appears as a small, blackish beetle, with gray 
pubescence, when the buds are developing, and lays an egg in 
each, afterward puncturing the flower-stalk be- 
low the bud so as to check development. The 
larva feeds upon the pollen in the unopened 
bud, and finds it sufficient to attain its full 
growth, changing to a beetle in midsummer. 
The insect attacks a number of other flowers 
in the same way, not even confining itself to 
one natural family, and its injury to straw- 
berries is of a somewhat intermittent character, 
becoming worse for a number of years, then 
stopping suddenly for no apparent reason. 
Only staminate, or pollen-bearing, varieties are 
attacked, and the Sharpless is, perhaps, the 
most seriously infested. By planting chiefly 
pistillate varieties, the staminate rows may be protected by cheap 
coverings until the buds are ready to open, and even if a small 



Rhubarb-beetle, Lixtis coticaviis. 
—a, its larva ; b, pupa. 



Fig. 2^,8. 




Strawberry-weevil, 
Anthonomus signatus. 



232 AN ECONOMIC ENTOMOLOGY. 

crop only is obtained on the pollenizers, the main crop will be 
safe without protection. Insecticides have not proved markedly 
useful in this case. 

Other species of this genus have proved more or less trouble- 
some, notably A. quadri-gibbiis, on apple, but none of these 

Fig. 239. 




Work of the strawberry-weevil.— a, shoot of strawberry-plant bearing punctured 
buds, b ; the egg at c ; larva at d; pupa at f ; at^ an open strawberrj'-flower showing 
the holes eaten by the beetles. 

require more attention here, and the next species in order is 
Conotracheliis nenuphar, the redoubtable " plum-curculio." 
Next to the "codling-moth," this is, perhaps, the most serious 
of the orchard pests, and it ranks above it in the difficulty attend- 
ing its control. The beetle itself is less than one-fourth of an 
inch in length, chunky in appearance, brown, with black and 
gray mottlings, and with four elevated excrescences on the wing- 
covers. The beetle hibernates and appears in early spring, feed- 
ing first upon the unopened buds and afterward upon the young 



THE INSECT WORLD. 



233 



Fig. 240. 




Plum-curculio, Conotrachelus ?ienu- 
phar. — a, larva ; b, pupa ; c, adult ; d, 
beetle at work on a young plum, show- 
ing a crescent mark. 



leaves of plum, peach, apricot, cherry, apple, and pear. When 
the fruit has set and become of the size of a marble, the insect 
makes a crescent-shaped slit, elevating a small flap from the sur- 
rounding tissue, and in this it lays an egg. The latter hatches 
in a few days, and the whitish, grub-like lar\^a bores at once to 
the seed capsule, causing the 
fruit to fall from the tree and rot 
in the plum, peach, apricot, and 
cherry, though, except in the 
plum, this dropping is not uni- 
versal. Apples and pears do not 
drop as a result of curculio in- 
jur}-, and, except in a few varie- 
ties of apples, the larva is unable 
to mature in the fruit remaining 
on the tree. In apples and pears 
that drop from other causes, the 
larva develops freely. By mid- 
summer, growth is complete, the 
larv'se leave the now decayed 
fruits and go underground to pupate, changing to the adult, or 
beetle, form a short time thereafter. These go into hiding almost 
immediately, and are not again seen until the spring following. 
Remedial measures in this case have not proved entirely satisfac- 
tory. The larva is beyond reach of all insecticides, and can be 
destroyed only by persistent and thorough gathering of all fallen 
fruit at intervals of a few days throughout the early part of the 
summer. Chickens, turkeys, hogs, or sheep accomplish the same 
purpose less completely and lessen if they do not prevent injury. 
The beetles may be reached by spraying the trees before the buds 
open with one of the arsenites, destroying them before they have 
a chance to oviposit. Spraying may be continued after the fruit 
has set, to kill the beetle while eating out its crescents. Some 
part of the fruit is always injured, though a sufficiently large 
percentage to pay for the insecticide application is usually saved. 
Jarring the trees every day or two over a sheet or other recep- 
tacle has been practised with good success, as the beetles drop 
readily and lie quietly for some time, especially early in the day, 
allowing themselves to be easily gathered up and destroyed. 



234 



AN ECONOMIC ENTOMOLOGY. 



This is one of those cases where persistent and universal practice 
is desirable to obtain the best results. 

An allied but larger species of the same genus without the 
elevations on the wing-covers is C. crataegi, which attacks the 
quince and sometimes does considerable injury, much as the C. 
iiemiphar does on the fruits above enumerated. The same 
measures are indicated here also. 

The potato-stalk borer, Trichobaris j-notata, is a small ash- 
gray weevil about one-sixth of an inch in length, with a black 



Fig. 241. 




Potato-stalk borer, T^-ichobaris trinotata. — Larva, pupa, and adult. 



snout and three small black spots at the base of the wing-covers. 
It lays its eggs into the stems and larger branches of the potato, 
horse-nettle, Jimpson-v/eed (^Datura stramonhmi) , and, perhaps, 
other Solanaceae, and the white larvae feed there until after mid- 
summer, changing to pupae at about the time when the potato- 
vines mature, and to adult beetles a short time thereafter. The 
beetles remain in their larval burrows during the winter, and may 
be easily destroyed by burning the vines immediately after the 
potatoes are harvested. 

The species of Balmiinus are known as nut-weevils, are of 
quite large size, clay-yellow in color, and with an exceedingly 
long and slender, black beak or snout. By means of this they 
puncture the burrs of young chestnuts, the husks of hickory and 
walnuts, and the green coverings of young acorns, reaching near 
the centre of the nut itself, and placing an egg in the hole so 



THE INSECT WORLD. 



235 



made. The lan^a hatches and the Httle wound through which 
the egg was laid heals so completely that no trace of it is visible 



Fig. 242. 




Work of the potato-stalk borer, Trichobaris 3-notata, in potato-vines. 



in the fully developed fruit. When the nut is ripe and drops to 
the ground the larva is full grown, and eats a round hole in the 



236 



AN ECONOMIC ENTOMOLOGY. 




Chestnut-weevil, Balmiimis rectus. — a, from 
above ; b, in outline, from side ; c, larva. 



shell through which it makes its way and goes underground to 
pupate. Thus it winters, and the beetles emerge in spring when 

the nut-trees are in bloom. 
Considerable injury is 
sometimes caused in cul- 
tivated chestnut groves, 
and the only way to avoid 
it is to gather the nuts 
systematically as soon as 
they fall, and either ship 
them at once, or store 
them in tight boxes or 
barrels, from which the 
larvae cannot escape when 
they come out. They will then be found at the bottom when 
the nuts are removed, and may be easily killed. 

In many localities corn is attacked soon after it shows above 
ground by insects known as " corn bill-bugs." These belong to 
the genus Sphenophoriis, and are black or brown, rarely gray in 
color, varying from one-fourth to half an inch in length, with 
very thick and hard wing-covers, which are ridged and punc- 
tured, as is also the thorax. They hide during the day in the 
soil at the base of the corn-plants, and kill them by boring 
little round holes in the stem. They are most frequent after 
timothy, especially on old sod, or when corn follows sedges or 
bulb-rooted grasses. It is in such places that the larvae live 
naturally, pupating in fall or early spring, and the beetles, finding 
on spring-ploughed land that their natural food is gone, attack the 
corn, which replaces and is nearly enough like it to be to their 
taste. The period of injury is usually short, and by delaying 
replanting a little, the new shoots escape attack. Fall ploughing 
old timothy sod or sedge-land is always indicated, and will gen- 
erally serve to reduce, if it does not entirely prevent, injury. 

To this same series belong the largest of our weevils, the Rhyn- 
chophorus palmarum, or " palm-weevil," which often exceeds an 
inch in length and whose fat, white larva, boring in palm, is said 
to be quite a delicacy to the taste of the aborigines of Central 
and South America. 

Much resembling it in shape but hardly exceeding one-eighth 



THE INSECT WORLD. 



237 



of an inch in length are the grain weevils, belonging to the genus 
Calandra. These are almost cosmopolitan, and infest stored 
grains of all kinds. They are black or brown-red in color, quite 
slender, and on a very small scale resemble the ' ' corn bill-bugs' ' 
in sculpture. They can be easily controlled by the use of bisul- 
phide of carbon poured on the grain in bins or other receptacles. 

Fig. 244. 





Sphsnophorus oc/ireus.— Adult, larva, and work in roots of Scirpus. 

covering with canvas or similar material to prevent the too 
rapid escape of the fumes which gradually permeate the entire 
mass of grain, killing everything in it. 

Closing the series we have the bark-beetles, or Scolytids, some 
of them called shot-hole borers from the little round holes with 
blackened edges which they make in wood and bark. Many 
species make prettily -figured burrows between the bark and sap- 
wood, while others bore into the solid wood, making longer or 
shorter galleries. Most of the species attack forest-trees, and for 
them reference should be had to Dr. Packard's work already cited. 



y4N ECONOMIC EXTOMOLOGY. 



These beetles differ from all the other weevils in their cyHn- 
drical form and very short snout, which is scarcely more than a 
slight prolongation of the head, and they are usually of small 
size, most of them not exceeding one-eighth of an inch in length. 



Fig. 245. 




Cala?idra granaria.—a, adult ; b, larva ; c, pupa ; d, C. oryza, adult. 

Scolytus rugulosus, the "fruit-bark beetle," is, perhaps, the 
best known, and certainly the most important economically, 
attacking deciduous fruit-trees of almost all kinds. The black 
parent beetles appear in early spring, and bore little round holes 
through the bark to the sap-wood. They then make a central 
burrow, on each side of which little notches are made to receive 
the soft white eggs. The larvae hatch very soon, and at once 
begin to make little burrows of their own, diverging as they 
move from the parent channel, and gradually enlarging them as 
they increase in size. When full grown they form a slightly 
enlarged chamber, in which they pupate, and when they trans- 
form to beetles, make their way out through little round holes 
in the bark. The whole period of development does not exceed 
a month, and there may be several broods during the summer 
from the same tree, the numerous galleries eventually girdling 
and killing it. 



THE INSECT WORLD. 



239 




These insects rarely attack sound, healthy trees, and this is a 
peculiarity of bark-beetles in general, though there are many 
exceptions. But just as soon as a tree becomes a little weakened 
through injury or from starvation, these 
Httle creatures attack it, and then its 246. 
doom is sealed, unless vigorous meas- 
ures are taken at once. Peach-trees are 
especially susceptible to injury, and the 
gummy oozings from the little holes 
seem to weaken them so rapidly that 
they succumb in a short time. 

It is good practice to keep orchard 
trees in the best possible health and 
vigor at all times to enable them to resist 
naturally the attacks of these insects, 
but if one does become seriously infested 

Fruit-bark beetle, Scolytus 

It should be at once cut out and burnt. ruguiosus, much enlarged. 
It is certain to die in a short time, and 

it is a constant menace to surrounding trees from the abundance 
of specimens which will be produced, ready to attack others at 
the least sign of weakness. Where a slight infestation is noticed 
on a tolerably healthy tree, it should be closely examined to 
ascertain the original source of weakness, and when this is re- 
moved the tree should be stimulated by means of appropriate 
fertilizers, and the trunk kept covered by whitewash to which 
Paris green has been added. Strong whale-oil soap-suds will 
answer the same purpose, and a little crude carboHc acid will 
add to its effectiveness. In all cases the application should be 
thorough, and should be kept intact until the tree has fully 
recovered and is able to take care of itself. 

The same line of treatment is adapted to other bark-beetles, 
varied according to the differences in life history. 

To recapitulate in a general way, beetles and their larvae are 
mandibulate and chew their food ; therefore, whenever they feed 
openly upon plant tissues, they may be killed by arsenical sprays. 
Internal feeders must be dealt with as indicated by their life 
habits, but we must look rather to preventive than to remedial 
measures in such cases. 



240 



A TV ECONOMIC ENTOMOLOGY. 



CHAPTER VII. 

THE LEPIDOPTERA. 

Butterflies and Moths. 

Under the term Lepidoptera are included those insects popu- 
larly known as butterflies and moths, in which the wings and 
body are more or less clothed with scales. These scales often 
differ greatly in form and size even in the same insect, and yet 
more in different groups, so that a certain family or series may 
show types peculiar to it alone. Oddly enough, there is some- 



FiG. 248. Fig. 249. 




Scales on wing of butterfly. b ; the appearance of tongue 

under a lens at c. 



times a difference even in the sexes, certain kinds of highly 
developed scales occurring on the wdngs of the male only, 
usually confined to limited areas and sometimes concealed by 
folds. 

In this order the adult insects are harmless throughout, capable 
of feeding only upon liquid food by means of a tongue which 
is usually coiled like a watch-spring on the under side of the 
head between the palpi. In some instances it is wanting, and 
on the other hand sometimes becomes enormously developed, 
reaching a length in some species of from five to nearly seven 



THE INSECT WORLD. 



241 



inches. Many of the Lepidoptera are useful in pollenizing 
flowers, some, indeed, depending entirely upon them for their 
continued existence, but, on the other hand, the caterpillars, as 
the larvae are usually called, are among the most troublesome 
and injurious insects with which the agriculturist has to deal. 
The transformation in this order is complete, and a greater 
difference than that between caterpillar and butterfly can hardly 
be imagined ; while in the chrysalis or pupa we have a quiescent 
period where scarcely even the form of the future insect is indi- 
cated, and when it is absolutely incapable of motion. 

Broadly, the order is divided into butterflies and moths, or, 
more accurately, the Rhopalocera and Heterocera. Rhopalocera 
are those in which the antennae, or 
feelers, terminate in a more or less Fig. 250. 

distinct knob or club at the tip, and 
in which at least the front pair of 
wings are elevated or vertical when 
at rest, so that the upper surfaces 
touch. The Heterocera, on the 
other hand, have feelers, or anten- 
nae, of many different kinds, but 
never in our fauna distinctly 
clubbed. The wings when the 
insect is at rest are horizontal, 
folded on the back or close to the 
sides, oblique, roof-like, or spread 
out flat, but never habitually ver- 
tical. In general it may be said 
that the butterflies are on the 
wing during the day, and fly dur- 
ing the night only in rare in- 
stances ; moths, on the other hand, 
are night flyers, as a rule, though there 
and a number of species occur commonly during the day. 

The butterflies separate readily into groups based on the char- 
acter of the feet and the situation of the antennae. What may 
be called for convenience the ' ' true butterflies ' ' are distinguished 
by having the feelers set close together on the top of the head, 
the latter being proportionately rather narrow. The antennal 

16 




Antennae in Lepidoptera. — a, 
clubbed antenna of butterfly ; b, c, 
variations in form of club; d, prismatic 
and fusiform ; e, ciliated ; f, bristle- 
tufted; g-, donhXy bipectinated. 



are many exceptions. 



242 



AN ECONOMIC ENTOMOLOGY. 



club is abrupt at the tip and not drawn out into a hook or 
recurved. In the skippers, or Hesperids, the head is broad, the 
eyes are comparatively small, the feelers are widely separated, 
set close to the eyes, and terminated by a pointed tip which is 
often recurved or hooked. 

A large series of the true butterflies is distinguished by having 
the anterior pair of feet more or less aborted or imperfect, and 
these, the ' ' brush-footed ' ' butterflies, are classed in two famiHes, 

Fig. 251. 



the NymphalidcB, containing moderate-sized or large species, and 
the LyccBiiidce, containing small species, in which the colors are 
blue or coppery, or have the under sides marked with fine, 
thread-like lines. They are the "blues," "coppers," and 
" hair-streaks." 

Among our most common species of the first family is the 
"milk-weed butterfly," Danais archippus, quite a large red- 
brown insect, with the wing-veins broadly black marked. It 
becomes abundant in late summer and fall, and its caterpillar, 
green in color, marked with black lines, and furnished with rather 
long, black, hair-like tentacles, may be often seen feeding upon 
milk-weeds. This species will serve to typify the family to w^hich 
it belongs, and is easily raised by any one curious to watch its 
transformations. If the caterpillar be confined with a sufficient 
supply of fresh leaves, it will grow to about an inch and a half in 
length, wall then fasten itself by means of its hind feet to a little 
pad of silk, and will change to a chunky, bright-green chrysalis, 
or pupa, marked with small golden spots, one of the prettiest 
objects that can be imagined. In a few days the color will be- 




a, head of Papilio, show- 
ing where antennae are in- 
serted ; b, same of an 
Hesperid. 



a, foreleg of a brush-footed butterfly entirely 
aborted ; b, oi Lyccsna, male, tarsus one-jointed. 



THE INSECT WORLD. 



243 



come darker, finally brown or blackish, and then the butterfly 
will emerge. This is not an injurious insect, and is only referred 



Fig. 253. 




D 

Milk-weed butterfly, Danais archippus , z.nd. its transformations.— ^, a, egg enlarged 
thirty diameters ; b, very young larva, showing how the tentacles are folded ; c, egg, 
natural size, on a leaf ; B, full-grown larva ; C, chrysalis ; D, male butterfly. 



to here because it is easily raised and common throughout the 
country, — in fact, has spread all over the globe. 



244 



A A' ECONOMIC EXTOMOLOGY. 



We have many species of considerable size belonging to the 
genus Argynnis^ which resemble each other more or less by 



in color, with irregular black or blackish blotches, spots, and 
lines, and a little silvery mark resembling a comma or semicolon 
on the hind wings beneath. Of these the caterpillar of G. comma 
feeds upon the hop-vine, although it rarely does any serious 
injury. It is reddish or yellowish in color, with a black head 
and black branched spines, and forms an angular chrj^salis which 
is suspended by the tail. The chrysalis is yellowdsh green in 
color, with prominently marked segments, and has the thorax 
produced into a somewhat acute process. 

Another very common, almost cosmopolitan butterfly, is the 
Vanessa ayitiopa^ popularly known as the "mourning-cloak." 
It is of a very dark, rich-brown color, with a broad yellowish 
border on both wings. It winters in the butterfly stage, and 
may often be seen on w^arm days in midwinter, fluttering about in 
the woods, w^hile it is the earliest of the butterflies to make its 
appearance in spring. The caterpillars feed upon quite a variety 
of plants, notably willow^ and poplar, and often in great colonies. 
When full grown they are two inches or more in length and black, 
with red-marked, branched spines. The chrysalis is suspended 
by the tail, and of a somewhat mouse-gray color, the segments 
marked with acute spines. This may under circumstances be- 
come a troublesome insect, but it is easily controlled, either by 
arsenical poisons, as the caterpillar feeds exposed, or by hand- 
picking, which is easy because of the gregarious habit when 



Grapta progne .—'Xs 'Wig's, of right side detached 
to show under side ; this is almost like G. 



comma. 




Fig. 254. 



their tawny upper sides 
marked with black spots, 
and by having the under 
sides more or less marked 
wdth silvery blotches, es- 
pecially on the hind wings. 
None of them are injurious, 
the lar\-ae feeding upon vio- 
lets. In the genus Grapta 
there are species with 
strongly and irregularly 
angulated and toothed 
wings, quite dark brown 



THE INSECT WORLD. 



245 



young. A number of other common species belong in this 
family, but, as they do not feed upon cultivated plants in suffi- 
cient numbers to attract attention, they need not be further 
considered. 

Fig. 256. 




Larva and chrysalis of Vanessa anttopa. 



Quite early in spring we may see, fluttering along the road- 
sides, little blue butterflies expanding less than an inch when the 
wings are spread, and without prominent markings of any kind. 
These belong to the family LyccenidcE, usually to the typical 
genus Lycceyia, and from them the term "blues," as a popular 
name, has been derived. Later in the summer we find com- 
monly bright coppery butterflies, not much larger than the 
* ' blues ' ' already spoken of, and on the upper surface, especially 



Fig. 258. 




Chrysophanus thoe. — Male and female. 



of the fore-wings, are black spots varying in size and arrange- 
ment. To these the name ' ' coppers' ' has been applied, and 
they' belong to the natural genus Chrysophanus. The genus 
Thecla contains species that run larger than either of those pre- 
viously mentioned, many of them sombre in color and marked 
on the under side by fine, hair-like streaks, differing in arrange- 
ment and not always present. These are called " hair-streaks." 



246 



AJV ECONOMIC ENTOMOLOGY. 



The hind wings are often furnished with one or two pairs of 
slender, thread-hke tails, easily broken off if the insects are care- 
lessly handled. None of the members of this family are injurious, 
and the somewhat slug-like caterpillars are not often seen. 
Fenesica taj'-quinius looks like one of the " coppers," and is pe- 
culiar in that its larva feeds on the woolly plant-lice often found 
on beech and other trees. It is the only butterfly larva in our 
country which is known to be predaceous. 

The family PapilionidcB contains six-footed butterflies, the 
anterior feet being perfectly developed in both sexes, and here 
the antenuce are set rather close together at the base. It includes 
our largest and brightest species, the most prominent of them 
being known as "swallow-tails." There are two groups, the 
first containing smaller species, which are white or yellow in 
color, the hind wings without tails, but furnished with a fold 
along the inner margin, forming a groove, in which the abdomen 
lies. These are arranged under the term PierincE, and contain 
as typical forms the common cabbage butterflies. The most 
abundant and injurious of these is Pieris rapce, an insect imported 
many years ago from Europe, and which has now spread over 
the largest part of the United States and Canada. The wings 
expand about an inch and a half, are white or with a creamy 
tinge, with a single black spot in the fore-wings of the male, and 
two similar spots in those of the female. There is also a little 
black patch at the apex, and on the under side the wings are 
usually darker and a little powdery. These butterflies appear 
very early in spring, emerging from chrysalids that have hiber- 
nated, and lay their eggs upon almost any of the cruciferous 
weeds. They are not particularly choice, but perhaps the com- 
mon Barbarea vulgaris is about as often selected as any in the 
Middle States, because one of the first to make its appearance. 
The first brood comes to maturity in less than a month, and then 
eggs are laid on early cabbage-plants. Soon irregular holes 
appear, first in the outer leaves, then in the head itself, and little 
piles of dirty-yellow excrement may now be found everywhere 
among the folds. The caterpillars themselves are veh-ety green 
in color, almost like the cabbage-leaf, and, as they lie rather 
closely to the plant tissue, are easily overlooked until a little 
practice is gained in searching for them. They become more 



Fig. 260. Fig. 265. 




Fig. 259, Thecla strigosa. Fig. 260, Pieris rupee, male. Fig. 261, Pieris rapcE, female. 
Fig. 262, a, larva ; b, chrysalis of Pieris rapcE. Fig. 263, Pieris protodice, male. Fig. 
264, Pieris protodice, female. Fig. 265, larva and chrysalis of P. protodice. 

247 



248 



AN ECONOMIC ENTOMOLOGY. 



abundant as the season advances, and late cabbage often suffers 
seriously in some localities. By all. odds the best remedy is 
spraying with the arsenites, at the rate of about one pound in 
one hundred and fifty gallons of water. A great many other 
remedies have been recommended, and some of them are un- 
doubtedly useful, but nothing is so satisfactory and cheap as the 
arsenite, and without gross carelessness there is not the slightest 
danger in the application. The cabbage heads from within, — 
that is to say, the leaves unfold from the centre of the head and 
do not fold together to form it ; therefore, whatever poison is put 
upon the plant can fall only upon the outer leaves, and not a 
particle gets into the head itself The -amount used to a single 
cabbage-plant is so minute that in order really to poison a man it 
would be necessary for him to eat about a dozen heads, outer 
leaves and all, and if death then resulted I would be inclined to 
attribute it rather to the cabbage itself than to the Paris green or 
other arsenite employed. The larvae succumb to the poison very 
readily, and by making the appHcation early in the season the 
later broods may be materially reduced in number. In ordinary 
farm practice the heads are cut out and shipped, and in prepar- 
ing the cabbage for food, the outer leaves of these heads are 
generally taken off by the housewife because more or less bruised 
or injured, before they are cooked. Chemical analysis has shown 
that on a head so prepared, within a week after a heavy applica- 
tion of Paris green, not a trace of arsenic remained. As a matter 
of fact, the use of Paris green as against the insect is quite 
common, although litde is said of it, to avoid exciting prejudice, 
and I have yet to learn of the first case of arsenical poisoning 
from eating cabbage so treated. From New Jersey southward 
and westward, one of our native species, P. protodice, becomes 
more common and assists its imported relative in making havoc 
among the cabbages, but this also may be easily controlled by the 
measures above detailed. 

We find flying abundantly in our fields, and more common 
among clover, a bright, sulphur-yellow butterfly about as large 
as the P. rapes, with a single black spot on the fore- wings, and a 
broad black outer margin to both pairs. On the under side the 
hind wings have a central orange spot, often with a slight silvery 
tendency. These butterflies belong to the genus Colias, and the 



THE INSECT WORLD. 



249 



Fig. 255. 




Fig. 255, mourning-cloak butterfly, Vanessa antiopa. Fig. 257, Lyccena pseudargiolus. Fig. 266, 
Colias philodice, male. Fig. 267, same, female. Fig. 272, Nisoniades juvenalis. 



250 



AN ECONOMIC ENTOMOLOGY. 



common eastern species, extending westward to the Rocky 
Mountains, is C. philodice, whose larva feeds upon clover. It is 
a green caterpillar somewhat similar to the " cabbage- worm," 
but although it may be quite abundant, rarely does injury enough 
to be noticed. As a rule, the larva is rather difficult to find, even 
where the butterflies are abundant, and practically no measures 
need be taken against it. 

In the sub-family PapilioiiincB we have in our country only the 
typical genus Papilio, containing species abundant enough to 
become of economic importance. The most common of these is 



Fig. 268. 




Papilio asterias, male. 



P. asterias, a black " swallow-tail," expanding between two and 
three inches, the hind wings tailed and excavated on the inner 
margin, so that the abdomen is free, not enfolded in a groove. 
The male is somewhat smaller than the female, and has a diag- 
onal row of yellow spots crossing the fore-wings outwardly and 
the hind wings nearly across the centre. Near the outer margin 
of both wings there is a row of yellow, lunate spots, and at the 
inner angle of the hind wings is a peculiar, eye-like spot, just at 
the margin. The female has the inner row of yellow spots very 
much reduced, sometimes altogether wanting, but on the hind 
wings the space between the faint series of yellow spots and the 
outer lunules is beautifully powdered with metallic blue scales. 
These butterflies lay their eggs on carrots, parsley, and other 
plants of the same natural family, and from them hatqh bright 



THE INSECT WORLD. 



green caterpillars with broken black bands. A peculiarity of 
this kind of caterpillar is that when touched or irritated in any 
way it shoots out from between the segments close to the head a 
forked, orange-colored process, which emits a very disagreeable 
odor, and this is its only means of defence. No trace of the pro- 
cess is visible when the insect is at rest, and the horns are with- 
drawn just as soon as irritation ceases. When the caterpillar is 
full grown it leaves the plants upon which it has fed and travels 
to any convenient point in the vicinity where it can pupate. This 
pupa, or chrysalis, is fastened to a little silken pad by the tail. 

Fig. 269. 




Papilio a^^frza^.— Mature larva and pupa. 



but is also sustained by a silken band in front of the middle, so 
that it is said to be girthed, and this same type we have in all the 
members of this family. These caterpillars are rarely abundant 
enough to become troublesome, but if they are, hand-picking is, 
perhaps, as good a remedy as any. They are quite prominent, 
and, therefore, easily and rapidly gathered, checking their injury 
immediately and completely. When they are small, spraying 
with the arsenites will answer, provided it be done thoroughly. 

Another species is P. p/iilenor, of about the same size, black, 
without the yellow spots through the centre, but with the upper 
surface overlaid with greenish, powdery scales, which give the 
insect a metallic lustre in certain lights, and this varies according 
to the angle at which the light strikes the wings. The cater- 
pillars feed upon vines of Aristolochia, or " Dutchman's pipe," 
which they sometimes injure considerably. They are dull 
brownish red in color, with long, fleshy filaments on the seg- 
ments, and when irritated also extrude fleshy horns such as 



252 



ajy economic entomology. 



already described and for the same purpose. The measures 
recommended for the parsley caterpillar may also be adopted 
against this insect. 




The largest of the common northern " swallow-tail" butterflies 
is the P. tur7ius, which expands from three to six inches, and is 



THE INSECT WORLD. 



253 



bright yellow in color, with transverse black bands. Towards 
the South and West, occurring rarely, however, as far north as 
Canada, we have a form of the female which is black, but may be 
distinguished by its large size from our normally black species. 
The caterpillar is green, and distinguished by having two black, 
eye-like spots on the anterior segments. It feeds on a number 
of different plants, but does not become economically important. 

In Florida, P. cresphontes is abundant, and its caterpillar is 
known as the ' ' orange dog, ' ' from its peculiar appearance and 



Fig. 271. 




The orange dog, caterpillar of Papilio cresphontes, with osmateria, or scent-organs, 
extended ; the detached figure shows the anterior segments normally retracted. 



habit of feeding upon orange-leaves. The butterfly is even larger 
than the tur?ms, and is black, with a broad diagonal band of 
contiguous yellow spots extending from the tip of the fore-wings 
towards the base, reaching the inner margin very near to the base 
of the hind wings. There is also a band of yellow spots near the 
outer margin, which are especially prominent on the hind wings, 
and a yellow spot occupies the centre of the broad, lobed tail. 
The caterpillars are prominent, as already stated, and orange- 
growers consider them among the greatest troubles of the young 
trees, especially in the nurseries, where a single specimen may 
defoliate a shoot in a little time. Hand-picking on small trees is 
a feasible and satisfactory remedy, and another is to capture the 



254 



AN ECONOMIC ENTOMOLOGY. 



butterflies on the flowers which they frequent during the middle 
of the day. Mr. Hubbard has suggested shooting them with 
cartridges loaded with sand, and that can easily be done during 
mid-day from a veranda or other shelter when the butterflies 
hover around the flowers near by. 

The ' ' skippers, ' ' or HesperidcE, differ from all the preceding 
by the broad head, clothed with bristly hair, and by the widely 
separated antennae, or feelers, the club being also terminated by 
a more or less marked and recurved slender booklet. They are 
small or moderate in size, and get the common name from their 
jerky habits of flight, usually along roads, and practically con- 
fined to low herbage. There are two rather well-marked, though 
by no means sharply limited sections, distinguished by color, the 
first containing dark, blackish or sombre brown types, and the 

other tawny yellow forms. 
Fig. 273. The former is represented 




by the species of Nison- 
iades and its immediate 
allies, and the latter by 
the genus Pamphila and 
allies. In this latter se- 
ries the fore-wings are 
much more pointed than 



Pampinia ethiius. in the Other, and the body 

is proportionately more 
robust. None of the species, so far as I am aware, are of eco- 
nomic importance, though our largest species, Megathyvius 
yucccE, does some injury by occasionally boring into the roots of 
the yucca plant. These insects have been considered intermedi- 
ate between the butterflies and moths, and many species have 
the habit of elevating the front wings only, the hind wings being 
held horizontally. 

The first of the Heterocera to be considered here are the 
SphiyigidcB, or "hawk-moths," and these obtain the common 
name from their habit of hovering about flowers, and their rapid, 
darting motions. Most of them fly just about dusk, visiting 
deep flowers like the "evening primrose," "petunia," or even 
" Jimson weed," and they succeed in reaching the very bottom 
of these by means of an unusually well-developed tongue. They 




nectaries, but rarely alighting. The antennae are prismatic and 



256 



AJV ECONOMIC ENTOMOLOGY. 



spindle-shaped, and terminate in a little, recurved hook. The 
body is robust and well developed, supported in flight by means 
of stout, though rather narrow, pointed wings. The caterpillars 
are peculiar in having a curved horn on top of the last segment, 
or in its place a hard, glossy, eye-like spot. When at rest, some 
of them have the habit of elevating the front part of the body 
and curHng the head under a little, giving them a fancied resem- 
blance to a Sphinx, and from this the scientific name has been 
derived. A very good example of a typical sphinx caterpillar is 
found in the large green species, the sides with oblique, lateral, 
white stripes, which is often found upon potatoes and tomatoes, 
occasionally doing considerable injury. The anal horn is quite 
often believed to be venomous, and all sorts of stories are told of 
people having been poisoned or stung ; it is even said sometimes 
that a stream of poison is thrown from the end of the horn for 
some distance. As a matter of fact, nothing can be more harm- 
less than these caterpillars ; there is no poisonous secretion 
connected with the horn, and they can be handled with absolute 
safety. This same type of caterpillar also attacks tobacco and 
other SolanacecB, and, when full grown, goes underground and 
changes to a mahogany-brown pupa an inch and a half to two 
inches in length, with a peculiar handle-like process attached to 
the head, which forms a covering for the future tongue. This 
has given them the name "jug-handle grubs" in some localities. 
The adults, when they emerge, expand from three to five inches 
or more, and are ashen-gray in color, the fore-wings with a 
little white spot near the centre, and crossed by irregular darker 
lines, the hind wings banded with black and white, while along 
the sides of the abdomen are five large yellow spots. This is the 
Sphinx (^Protoparce) caroli7ia, which may be accepted as typical 
of the series to which it belongs. An allied species, Protoparce 
celeus, feeds on the same kinds of plants, and resembles the 
Carolina rather closely, except that the yellow of the abdomen 
is paler, the lines on both wings are rather more distinct, and 
the insect is a little larger ; but the difierences are not great, and 
need not be further detailed here. Other species of sphinx 
caterpillars are found on a variety of other plants, but they do 
not often appear in noticeable numbers, being much subject, from 
their large size, to the attacks of birds and parasitic insects ; so, 



THE INSECT WORLD. 



257 



except for the species already mentioned, nature herself keeps 
down the insects to a reasonable number. 

Another series of this same family is more brightly colored, 
with the wings angulate, dentate, or only a little sinuate at the 
outer margin, and of these we have several species that attack 
the vine. The caterpillars are rather more clumsy than those of 
the preceding series, and the head is often retracted into the 
enlarged thoracic segments. The horn is frequently wanting and 
replaced by a shining, usually blackish, eye-spot. These are 
known as * ' hog-caterpillars, ' ' and often appear in numbers 
sufficient to cause more or less injury in vineyards. The adults 
are brightly colored, either greenish with darker, blotchy mark- 
ings, or reddish with brown markings, or a combination of olive 
green and rusty brown and gray. The figures herewith given 
illustrate the more common species, and as their habits are much 
the same, no special description of each is needed. 

On the elm-tree we sometimes find a green caterpillar, the skin 
a little roughened, with the typical sphinx anal horn and, in addi- 
tion, four little horns on the anterior segments. This is the larva 
of Ceratomia amyntor^ or, as Dr. Harris called it, much more 
appropriately, quadricornis, which means four-horned. The 
moths produced by this caterpillar may often be found in mid- 
summer on the trunks, and are dirty yellowish gray, streaked 
with blackish, and with white discal spots. 

Sometimes we find, flying around flowers in bright sunlight, 
exceedingly active little creatures that at first sight resemble 
humming-birds, and are frequently considered such. If they be 
captured, however, we see that they are brilliantly colored moths, 
which have received the common name "humming-bird hawk- 
moths. ' ' They usually have the fore-wings quite sparsely clothed, 
sometimes nearly transparent, while the body is covered by rich 
coppery or other metallic-colored scales. 

The caterpillars in this family are all external feeders, and 
usually so large and prominent that they can easily be seen. In 
most cases, therefore, the simplest remedy is hand-picking, but 
when this is done no caterpillar should be destroyed which is 
covered with little, white, egg-like bodies, for these are the 
cocoons of parasites which do much to keep the insects in check. 
Where the larvae are abundant enough to make hand-picking 

17 




Fig. 275, Philampelus pandorus. Fig. 276, Philampelus achemon, larva. Fig. 277, 
Philanipelus achenion. 



THE INSECT WORLD. 



259 



impracticable, any of the arsenites may be employed. The 
attempt has been made, not without a fair degree of success, to 
protect tobacco plants by killing off the moths while feeding in 
the flowers of the "Jimson weed," a few drops of a poisonous 
solution being placed in the bottom of each flower. It is perhaps 
questionable whether the results obtained justify the method 
from a practical stand-point, and the direct application of poison 
to kill the larvae is, all things considered, the most satisfactory. 

Following the hawk-moths in our lists, but not in the least 
related to them structurally, are the clear-winged moths belong- 
ing to the family SesiidcB. They are slender bodied, with quite 
long antennae, the wings narrow, often without scales, the colors 
metallic or at least glistening, and usually bright and contrasting. 
They often resemble and are considered wasps or hornets from 
their appearance, the more so because it is quite usual for them 
to have the abdomen banded with yellow. These creatures are 
the parents of borers that are among the most injurious to culti- 
vated plants. 

First in the series is the ' ' squash-borer, Melittia ceto. This is 
readily recognized in the adult stage by the opaque, greenish 
fore-wings, and by the unusually large, thickened hind legs, 
tufted with black and orange, giving the insect a characteristic 
appearance, different from any other common species. It may 
be found during late spring or early summer hovering about the 
squash or other cucurbit plants during the day, but in the even- 
ing and during the night resting exposed upon the leaves. It 
lays its eggs preferably on the vine just at the surface of the 
ground, if the soil is light even a little below, but it is by no 
means confined to this point, and may lay them anywhere, even 
on a leaf or leaf-stalk. They are brown in color, disk-like, and 
have a very brittle shell. The larvae when hatched are white or 
nearly so, with a small brown head, a full complement of legs, 
and at once bore into the stem of the vine. Preferably they live 
just at the surface of the ground, really eating very little of the 
plant, but rather they suck the juices, causing its enfeeblement 
and ultimate death. When full grown in midsummer the larva 
goes a short distance underground and forms a very tough, 
parchment-like cocoon in which it rests until the year following. 
In spring the pupa, by means of its chisel-like head-case, cuts a 



26o 



AN ECONOMIC ENTOMOLOGY. 



circular lid from the cocoon, wriggles its way to the surface, and 
through it into the open air. This has long been a pest to 
squash-growers, and the usual remedy is cutting them out when 
the wilting vines denote their presence. This is quite practical, 
but has the disadvantage of being very slow, besides having a 
tendency to injure the vines if the cutting is unskilfully done. 
Care must be taken to cut only longitudinally, while the wounds 
should be rubbed with dry soil and covered with earth to facilitate 
healing. Covering the joints to induce rooting is advantageous, 
because it gives new sources of supply for plant food ; so that even 
if the vine be entirely severed at the original root, it may mature 
fruit from the suckers. Where squashes are raised on a large 
scale, the best method is to trap the insects by a first crop of 
some summer variety, preferably crook-necks. These grow 
rapidly, and the moths readily lay their eggs upon them, the 
plants continuing to do well even when infested by the larvae, 
and maturing an early crop of fruit. The late squashes, Hub- 
bard or marrowfat, may be planted when the summer varieties 
are well under way, and by the time they are large enough to 
be attractive to the moths, most if not all the eggs will have 
been laid, and they will be practically exempt. As soon as the 
late varieties need the ground the sum- 
mer variety should be carefully removed, 
the plants being taken out entire and 
destroyed, and with them the brood of 
contained larvae. In other words, the 
summer squashes are to be used as a 
trap crop to protect the Hubbard, mar- 
rowfat, or other main, late variety. It 
should be said that in the Central and 
Southern States there are two broods 
of these insects, and even on Long 
Island, New York, a few specimens are 
occasionally found in September. Vigor- 
ous war on the first brood, however, by 
means of traps will prevent injury from 
the second. 

Blackberries are often attacked by a similar larva at the surface 
of the ground or a little below it, boring sometimes a little dis- 




Bembecia marginata.—a, 
male ; b, female. 



THE INSECT WORLD. 



261 



tance up or down the cane or completely around it, for which 
reason it has been called the ' ' blackberry crown-borer. ' ' Signs 
of its presence are the sudden wilting and rapid death of new 
shoots, and it comes to maturity in early September of the 
second year of its life, forming a pupa in the stalk itself. The 
resulting moth, Beinbecia marginata, is black, very little marked 
with yellow, and the only satisfactory remedy is cutting out and 
destroying the larva as soon as its presence is indicated by the 
wilting leaves. 

Perhaps the best known of all belonging to this series is the 
"peach-borer," Sannijia exitiosa. This is the pest of peach- 
growers all over the country, and the larvae live between bark and 
wood a little below the 
surface of the ground in 
a mass of gum and woody 
material. They first 
make their appearance 
after midsummer, and 
become about three- 
fourths of an inch long 
before winter sets in. In 
spring they resume feed- 
ing, attaining a length of 
a little more than an inch, 
then spin a cocoon of 
silk and bits of chips 
covered with gum, and 
change to a pupa. In 
this stage they remain a 
few days and then emerge 
as moths. The sexes are 
very unlike, the males 
black, with narrowly yel- 
low-banded abdomen, 
and entirely transparent wings ; the females much larger, the 
fore-wings almost blackish brown and entirely covered with scales, 
the abdomen black, with a broad orange band at about the 
middle. The eggs are laid on the bark near the surface of the 
ground, and the larvae hatch after midsummer in time to do con- 




The peach-borer, Sanytina exitiosa; male above, 
female below ; both enlarged. 



262 



AAT ECONOMIC ENTOMOLOGY. 



siderable feeding before winter arrives. ' ' Worming' ' peach- 
trees, or cutting out the larv^, is a recognized method of getting 
rid of these insects, and has the advantage of being effective, if 
thoroughly done. It has the disadvantage of gashing the trees, 
and sometimes causing a considerable amount of injury before 
the insect is found. If carelessly done a few will escape, and 
sooner or later the tree becomes girdled at the base, or so 
weakened that it proves attractive to bark-beetles, who complete 
the work begun by the borers. Our task is to keep the insects 
out if possible, and the best method is to cover the bark with 
some material upon which the insect cannot lay its eggs or through 
which the young larvae cannot penetrate. On old trees white- 
lead paint in boiled linseed oil is about as good as anything, but 
it should not be used on young trees, nor should turpentine be 
used to thin out the lead in any case. On younger trees white- 
wash thoroughly applied and kept on from quite early in the ' 
spring until after midsummer will answer the same purpose, but 
as this washes off readily, it must be renewed as often as the 
coating becomes imperfect. Quite a satisfactory method is to 
wrap newspapers or tarred paper around the lower two feet of 
the trunk, hilling up against it at the base and tying at the top. 
This must be replaced yearly, but is an effective protection when 
well put on. Fine wire netting will answer the same purpose, 
and has the advantage of being more lasting ; or an application 
of *' insect lime" or " dendrolene," applied early in the season 
and maintained until midsummer, will serve perfectly. Anything, 
in fact, that forms a mechanical protection to the tree will 
answer, and this is the most satisfactory method of keeping out 
borers generally. 

There are other species of this family boring in maple, and 
their empty pupa shells may often be seen sticking out of the 
bark ; and so plum, pear, and a great variety of other trees are 
sometimes attacked. Where maples are to be protected, the 
whitewash affords the best hope of success, unless wire netting 
much finer than the ordinary mosquito screening is employed. 
Sesia acerni^ the ' ' maple clear-wing, " is a slender-bodied little 
creature, prettily marked with red and yellow, and would be 
able to oviposit through the meshes of an ordinary mosquito 
screen without trouble. 



THE INSECT WORLD. 



263 



Currants and lilacs are frequently attacked by borers of this 
family, and on currants considerable injury is sometimes done by 
Sesia tipiiliforrnis. Here the best remedy is to cut out the dead 
stalks in spring, just as soon as leafing out shows where the 
attack is located, and every wilted shoot seen at any time should 
be cut off at once below the point affected. The cut stems must, 
of course, be burnt immediately. An occasional liberal pruning 
back will prove useful in keeping dow^n the insects, and is some 
times a benefit to the plants as well. 

As a whole, we may say that our methods of treatment of this 
family are in the nature of prevention where the species attack 
trees, and cutting out where they attack shrubs or herbaceous 
plants. 

Grape-vines, especially in city gardens or in villages, are often 
attacked by light-brownish caterpillars with black dottings, 
which are sometimes so abundant as actually to defoHate them. 
They become nearly an inch 

and a half in length when full ^'^^^ ^83. 

grown, then bore into any soft, 
rotten, or even comparatively 
sound wood, where they pupate 
and eventually emerge as active 
little moths, expanding rather 
more than an inch, with black 
fore-wings having two pale yel- 
low blotches, and black hind 
wings with two white spots, of 
which that near the base is 
much the largest. The shoul- 
der tippets are yellow, and the 
insect is active during mid-day, 
hovering about the vines in the 

brightest sunshine. It is the Alypia octo-maculata, or 8-spotted 
forester, common throughout the Eastern and Central United 
States on wild as well as cultivated vines and Virginia creeper, but 
rarely troublesome, except near or in cities or towns. The cater- 
pillars feed quite exposed, and may be easily destroyed by means 
of the arsenites. In city gardens, pyrethrum in the form of a 
spray, two ounces to a gallon of water, will prove sufficiently 




Alypia octo-maculata, 8-spotted forester. 
— a, larva; b, an enlarged segment; c, 
the moth. 



264 



AA" EC 0X0 MIC EXTOMOLOGY. 



effecti\'e, especially if applied while the caterpillars are still quite 
small. 

Arranged in the same family, Agaristidcs, are several similar 
caterpillars, producing quite different moths, but amenable to the 
same methods of treatment. One species, the larva of Psycho- 
viorpha epimenis, folds the edges of the leaves and lives in the 
little pocket so formed ; but they are usually so rare that they can 
hardly be termed injurious. 

In that part of the Southern States where the "moon-vine," 
IpomcEa, flourishes, it is often attacked and sometimes defoliated 
by a yellow, hairy caterpillar, which appears in considerable 



Fig. 284. Fig. 2S5. 




Psycho7norpha epimenis. — Male insect Euchromia ipomcECE. 

and larva. 

numbers. When this is full grown it denudes itself of hair, and 
with it and a few threads of silk forms a bright yellow cocoon, 
from which issues in due time a wasp-like moth expanding 
nearly an inch, with narrow, white-spotted black wings, and a 
black, bright red or yellow banded abdomen. This is EucJwo- 
viia ipomcECB, which flies rather heavily and clumsily during the 
middle of the day in bright sunlight. As against this insect the 
arsenites are indicated, or, where only a few plants are to be 
protected, hand-picking may be resorted to. 

In vineyards there may be often seen feeding on the under 
sides of the leaves little, black-spotted, yellow, somewhat hairy 
larvae, less than half an inch in length, ranged side by side as 
closely as possible, and retreating as they eat until a leaf is com- 
pletely skeletonized. When this kind of lar\'a is full grown it 
spins a white, flattened cocoon, in which it changes to a pupa 
and from which it emerges in due time as a little, narrow- 
winged, black moth wearing a red collar. This is the Harrisina 



THE INSECT WORLD. 



265 



americana^ and certain varieties of grapes are occasionally in- 
jured by its larva. Feeding in colonies, as it does, the insect is 
easily checked by local applications of the arsenites. 



Fig. 286. 




Grape-leaf on which larvae of Harrisma mnericana are feeding. 

We now enter into a series of species the caterpillars of which 
are known as " woolly bears," from the fact that they are all 
clothed with long hair. In some cases this hair is so dense that 
the body of the caterpillar itself cannot be seen at all, and all 
these are of the Arctiid series. They spin a small quantity of 
silk only, and use the hair with which they are clothed in con- 
junction with it to form the cocoon. Under the microscope it 
may be seen that it is furnished with small spurs or branches, by 
means of which the insect is able to produce a felt-like material, 
needing only a small quantity of silk to hold it together in a 
tissue sufficiently firm for its purpose. Perhaps the majority of 
the caterpillars of this series feed upon low plants, and frequently 
it does not matter much what. Plantain seems to be a common 
food for many species, but they eat grasses as well, and, indeed, 
almost anything. They are often found in gardens attacking 
lettuce and cabbage, and on cabbages they are sometimes trouble- 
some in the field. Some are almost white or yellowish, and vary 



266 



A AT ECONOMIC ENTOMOLOGY. 



to brown or reddish, sometimes even to blackish, the hair being 
of the colors indicated, and the surface of the body hardly visible. 
The commonest of all, perhaps, is the Spilosoma virginica, or 
"white ermine moth," and this is whitish or yellowish, produc- 
ing a snow-white moth, the wings a little black dotted, the sides 
of the abdomen and front legs yellow. Another species often 
seen crawling about during late fall is Pyrrhardia isabella^ and 



Fig. 287. 




a: 



Spilosoma virgmica, the white ermine moth. — a, larva ; b, pupa ; c, adult. 

this caterpillar may be recognized by having the central portions 
of the body red-brown, while the anterior and posterior segments 
are black. This produces a uniformly brownish- yellow moth. 
All the moths fly at night, and are but rarely seen during the 
day, and all the caterpillars, where they become troublesome, 
are within reach of the arsenites. 

An exception to the general feeding habit we find in Hyphan- 
tria amea, the caterpillar of which is known as the " fall web- 
worm." The moth is white, sometimes without spot or mark 
of any kind, usually with only a few black dots, but occasionally 
with the spots forming more or less evident bands across the 
wing. The eggs are laid in masses on trees, and the larvae, as 
soon as they hatch, form a little web in which they remain so- 
cially, except when feeding. They eat first the leaves within, 
then those close to their nest, gradually separating until some- 
times an entire tree becomes defoliated from a single point. This 



THE INSECT WORLD. 



267 



species often becomes a serious pest in cities on shade-trees. 
There are two broods, the second being usually the one most 

Fig. 288. 




The fall web-worm, Hyphantria cunea.—a, b, c, varieties of larva ; d, e, pupa ; /, moth of 
the normal white form. 



noticeable, whence the nam.e " fall" web-worm, to distinguish it 
from the common orchard tent-caterpillar, which appears only in 



Fig. 289. 




Hyphantria cunea: variations in the markings of the wings. 

spring. A large variety of trees and shrubs is attacked by this 
insect, and where abundant it becomes a great nuisance. Usu- 



268 



AA^ ECONOMIC ENTOMOLOGY. 



ally its natural enemies keep it in check, but sometimes it seems 
to outrun them, and then for a series of years in succession it 
becomes increasingly abundant until, as suddenly as it increased, 
it disappears so nearly that nothing will be seen of it for a few 
years. If the insect is taken in hand as soon as noticed, cutting 
down and destroying the newly formed nests with all the cater- 
pillars they contain will prove the most satisfactory remedy, or 
the foliage just surrounding them may be sprayed with an arsen- 
ical mixture. 

There are other species in this series, like those belonging to 
the genus Halisidota, which sometimes infest shade-trees, but 
rarely in numbers sufficient to be troublesome. The caterpillars 
may be distinguished by having slender pencils of hair, and some- 
times a series of dorsal tufts. The moths are brownish yellow, 
with rows of semi-transparent and irregular, light-brown spots 
arranged almost in bands. Economically none others of the 
Ardians are troublesome, though we have many species that are 
common enough when sought for. 

In the family LyniantriidcB we ha^'e what are known as the 
' ' vaporer, " or " tussock moths. ' ' Of these the Notolophus 
{Orgyid) leucostig7iia, or "white-spotted tussock-moth," is 
the most common. It feeds on a great variety of trees in the 

larval stage, and is 
iG. 290. ^ seriously troublesome 

in cities and towns. 
The caterpillars are 
^f^^s^t- rather pretty creat- 

ures, with bright red 
i ^-^^ heads resembling 

- sealing-wax in ap- 

^'^""^^^''^ ^^^^^—^ pearance, and yel- 

Q.^X^rvyiW'^'! oi Notolophus leiicostis:ma. . it 1 

low bodies bearmg a 

series of dense, abruptly cut off brushes on the middle of the 
back, and two pencils of black hair anteriorly. They are rather 
more than an inch in length, when full grown crawl down the 
trees, and, either on the trunk or somewhere in the vicinity, under 
anv projecting point on fence-rail or the like, make their dirty- 
whitish cocoon of mixed silk and hair. In due time the adults 
emerge, the male bearing fully developed wings, while the 



THE IXSECT WORLD. 



269 



female has no trace of them whatever. The wings of the male 
are dusty gray in color, crossed by rather distinct, blackish lines, 
and with a litde white spot near the outer lower angle, which 
gives the insect its name, leiccostigma. The antennae are prom- 
inentiy feathered or pectinated, and the forelegs are long, very 
prettily tufted, and held when at rest projecting some distance 
forward. The insect is not often seen during the day, and usu- 
ally rests concealed until nightfall, when it seeks its mate. The 
female can be distinguished in the pupal stage by its larger size 
and the absence of wing pads. When it crawls out upon the 
surface of its cocoon it is a grub-like creature with a very heavy 



Fig. 291. 




The vaporer moth, Sotolophus leucostigma.—a, wingless female on her egg-mass ; b, 
young larva ; c, female, d, male pupa ; e, male moth. 

body, rather short legs, small head, and very short antennae. 
Neither of the sexes are capable of feeding, and as soon as the 
male has found the female, oviposition begins. The eggs are 
deposited upon the cocoon from which the female emerged, and 
as laid they are covered with a snow-white, frothy mass which 
hardens almost immediately into a brittle material that serves as 
a protection. The first brood of moths appears about midsum- 
mer, and from the eggs then laid the little caterpillars hatch in a 
few days ; these in turn become adult in fall, and eggs then laid 
remain throughout the winter, the prominent white masses soon 
turning gray and dirty, and hardly conspicuous on the trees or 
other surroundings to which they are attached. In the more 
northern States there is a single brood only. These insects when 
troublesome to shade-trees are easily dealt with : if all the egg- 
masses are removed and destroyed during the winter, the tree 
will remain clean during the ensuing summer, provided caterpillars 



AN ECONOMIC ENTOMOLOGY. 



are prevented from crawling up the trunk from the surrounding 
points. A band of " dendrolene" six inches in width and half an 
inch thick on a sheet of heavy wrapping-paper will serve as a 
complete protection if the tree has been cleared of eggs during the 
preceding winter. It is easy to see how this is done ; the female 
is absolutely incapable of flight, and no eggs can be laid upon a 
tree until a caterpillar has first made its way upon it and has 
changed to a female moth. Instead of " dendrolene " a broad 
band of fluffy cotton will answer for a time, as the caterpillars 
become entangled in and are unable to cross it. This sort of 
protection must be carefully watched, however, because other- 
wise the wet and dirt will harden and cause its failure to act as a 
bar. A trough of oil or an inverted tin cone tightly fixed to the 
tree may also serve, as will anything else that prevents the cater- 
pillars from crawling upon the tree. 

Belonging about here in the series comes the European 
''gypsy moth," Ocneria dispar, which, imported into Massa- 
chusetts in 1868, has caused enormous damage in that State, and 
has cost annually many thousands of dollars to keep it in check. 
The caterpillar when full grown is about one and one-half inches 
in length, of a creamy white, so thickly sprinkled with black that 
it seems dark brown, the ground color appearing in the broken 
dorsal and lateral lines. It is furnished with distinct dorsal and 
lateral tubercles, blue anteriorly and crimson behind the fifth 
segment, from each of which arise tufts of long black and yel- 
lowish hair. It changes to a chocolate-brown pupa, held in place 
by a few threads forming the merest apology for a cocoon, from 
July to September, and a few days thereafter the moths emerge. 
The males expand from one and one-half to two inches, are 
brownish yellow in color, the secondaries paler with a darker 
outer margin, the primaries smoky with darker, irregular, trans- 
verse lines. The females are much larger and more heavily 
built, the wings often expanding two and one-half inches. They 
are creamy white in color, the irregular, transverse lines gray or 
blackish. They lay their eggs in masses of from four hundred to 
five hundred in all conceivable localities, and cover them with 
yellow hair and scales from the end of the abdomen. They are 
deposited from July to late in September, and the larvae hatch 
early the following year, ranging from April to June, according 



Fig. 304. Fig. 295. 




Fig. 292, larva of gypsy moth. Figs. 294, 295, gypsy moth, Ocneria dispar, male and 
female. Fig. 304, Anisota senatoria, larva. Figs. 305, 306. Anisota senatoria, male and 
female. 



i 



THE INSECT WORLD. 



271 



to temperature and location. The fight against this insect is told 
in the reports of the Gypsy Moth Commission of Massachusetts, 
and these have been distributed wherever the insect has made its 
appearance. It has not as yet extended beyond Massachusetts ; 
hence details as to its destruction are not in place here. It is, 
perhaps, the most dangerous pest ever introduced into the 
United States, and should the State of Massachusetts abandon its 
campaign against it, the annual charge upon the farmers of the 
country would become enormous, if not ruinous. 

To the family Eucleidcs, or Limacodidcs , belong a series of 
rather modest green and brown moths, usually small in size, very 



Fig. 296. 




The saddle-back caterpillar and its moth, Empretia stimulea. 



densely clothed with scales and hair, the head much reduced, 
and the tongue wanting. This, by the bye, is quite a general 
character in the types now under consideration, and which are 
termed "spinners," because most of the caterpillars make a 
more or less complete cocoon of silk. The Limacodids are rarely 
common, and only one species, Empretia stimulea^ has become 
troublesome in the caterpillar state. This is a very curious, slug- 
like larva, somewhat flattened and oblong in shape, most of the 
body green in color, but with a quadrate, red-brown patch 
resembling a saddle on the middle of the back, and a brown 
patch at each end of the body, from the outer edge of each of 
which arises a long, fleshy process, set with stiff spines in all 
directions. Small warts or processes are found along the sides 
of the body, set with stiff hairs in the same way. It has no ap- 



2 72 AA^ ECONOMIC ENTOMOLOGY. 



Fig. 297. 

I ■ . ; . ■ 




A tubercle from a saddle- lj.u k moth, Empretia sn>iiu. u. bliowingthe poisonous spines, very 
much enlarged. The short pointed tips break off readily and remain in the wound. 



THE INSECT WORLD. 



273 



parent legs, but seems to crawl directly upon its belly, as do all 
the other caterpillars of this family, most of which have similar, 
though less developed, spinous processes. Another peculiarity 
which this species shares with others in the family is, that when 
handled, it causes a burning pain as if nettles had been touched. 
The hollow spines are terminated with easily detachable, very 
short, stiff tips, and at their base is a gland which secretes an 
urticating liquid. Handling the caterpillars roughly results in 
breaking off the little tips, which enter the skin and at the same 
time release a little drop of liquid, which, entering the wound, 
causes the burning sensation. With some persons this becomes 
a serious matter ; first inflammation, then swelling sets in, and in 
extreme cases a numbness or partial paralysis of the entire limb 
ensues. As a rule, however, the irritation is local, and no worse 
than would result from handhng a nettle. The prompt applica- 
tion of ammonia, bicarbonate of soda, or even strong brine 
will generally act as an antidote. This saddle-back caterpillar 
lives on a great variety of plants, including pear and rose, on 
which it is sometimes found in numbers. When full grown it 
spins an oval, brown, parchment-like cocoon, and in this remains 
unchanged until spring ; then it transforms to a pupa, and from 
this issues a brown moth, expanding less than an inch, and 
known as Empretia stimulea. A number of other caterpillars of 
this family attack fruit-trees, but always in such small numbers 
that they can hardly be considered injurious. 

The family PsychidcE is peculiar in that the larvae are encased 
in sac-like structures which they carry about with them, and 
from which they derive the common term "bag-worms." The 
best known of these, "the" bag- worm, is Thyridopteryx ephem- 
ercsformis. This is often common in orchards, and also attacks 
shade-trees, but is perhaps most injurious on arbor-vitae hedges, 
which it sometimes kills. On deciduous trees the insects are 
usually noticed during the winter, when there may be found 
hanging to the twigs and branches cone-shaped bags of silk 
varying from a little less than an inch to an inch and a quarter in 
length, and studded with bits of sticks and leaves. If the 
smaller of these bags are cut open at this time there will be found 
an empty pupa shell, but in the larger there will be found a mass 
of yellow, fluffy material embedded in which is a great mass of eggs. 

18 



274 



J AT ECONOMIC ENTOMOLOGY. 



In the spring these eggs hatch, and the Httle larvae make their 
way out through the mouth of the bag and feed upon the leaves, 
at once constructing for themselves a case made of leaf fragments 
held together with silken threads. At this time the bags are 
carried upright, and the insects feed on the upper surface of the 
leaf As the larva grows it enlarges its habitation, which soon 
becomes too heavy to be maintained in an upright position, and 



Fig. 298. 




The bag-worm, Thyridopteryx ephe^nercEformis.—a, larva; b, male pupa; c, female; 
d, male moth ; <?, bag of female cut open to show the mass of eggs ; f, caterpillar with 
bag in normal position ; g, young larvae with bags carried upright. 

drops ; the insect continues to feed, attaching the bag by means 
of silken threads to twigs when not moving about from place to 
place. Late in summer the larvae become full grown, and 
wander, sometimes leaving the trees altogether and fastening to 
fences or other shelter in the vicinity, and it is this habit that 
provides for the spread of the insects. When they have reached 
a place that suits them, the bags are firmly fastened, the opening 
is closed, and the caterpillars change to pupae. Shortly after the 
male emerges, and this is a black moth with transparent wings, 
short, feathered antennae, and an unusually long, tapering body. 
It is quite active and seeks the female, which forms only an 
imperfect sort of pupa, and even in the adult condition is a non- 
descript without trace of wings and almost without antennae. 



THE INSECT WORLD. 



275 



It is, indeed, a helpless, grub-like creature that awaits the visit 
of the male without making an attempt to emerge from its sac, 
in which it remains even after impregnation. The eggs de^•elop, 
finally fill up the bag, and then 
the female dies, the eggs rest- 
ing in the fluffy mass already 
described until the spring fol- 
lowing. 

This species is best treated 
by picking off and destroying 
the bags during the winter, and 
if this is thoroughly done no 
caterpillars will appear on the 
trees in the spring, unless they 
crawl on from other points 
where an egg-sac may happen 
to be attached. The meas- 
ures recommended against the 
"white-marked tussock moth" 
can be employed here as well, 
and trees once cleared can be 
kept free without much diffi- 
culty. When arbor-vitse is at- 
tacked, the picking should be 
thoroughly and carefully done, because these hedges suffer very 
rapidly, and once defoliated, usually die. In orchards where 
spraying is done against the codling-moth, the "bag-worms" 
are destroyed incidentally and no special measures need be taken 
against them. 

Next follows the family of ' ' prominents, ' ' so called from the 
fact that the moths frequently have a tooth at the inner margin 
of the fore wings, and the caterpillars are sometimes a little 
humped. They are technically termed Notodontid^s. Most of 
them have a small, retracted head, many of them a short or 
obsolete tongue, and some are more or less troublesome on cul- 
tivated plants. 

One of the best known is the ' ' yellow-necked caterpillar' ' 
often found feeding on apple-trees in colonies of from fifty to 
more than one hundred. When full grown it is nearly two inches 




The bag-worm. — a, sack of female cut 
open to show the grub-like creature at its 
mouth ; b, the female removed from the 
bag, much enlarged. 



276 



A A' ECONOMIC ENTOMOLOGY. 



in length, with a black head, a yellow neck, and the rest of the 
body yellow and black spotted. It has a peculiar habit of hold- 
ing by the false legs only and dropping the head and anal seg- 
ments when at rest. The insects feed very rapidly and often 
defoliate large branches before their presence is realized. When 
full grown they descend to the ground, burrow a short distance 
beneath the surface, forming a conical pupa, and remain in that 
condition during the winter. In spring the moths emerge, and 
are of a brownish-yellow color, crossed by rather even, narrow, 



Fig. 300. 




The yellow-necked caterpillar, a; its parent, Datana ministra, at b ; eggs, natural size 
and enlarged, at c and d. 

brown lines ; and this species is Datana ministra. It lays its 
white eggs to the number of nearly one hundred on the under 
side of apple and other leaves in a single layer. Similar cater- 
pillars may be found on a variety of other plants. The sumach 
is often defoliated, walnut- and oak-trees have their own species, 
and in all cases the moths have the general appearance already 
described. Insects that feed thus in company are controlled 
without difficulty, if we attack them as soon as the colony has 
hatched. They are then confined to a few leaves, and if these 
be picked off and destroyed, injury is avoided for the season. If 
this is not possible, or the colony has already spread too great a 
distance, then spraying the infested branch with arsenites will 
answer every purpose. 

There are other caterpillars of this family that attack fruit-trees, 
but as a rule in such small numbers as to be harmless. 

Oak-trees are occasionally attacked and defoliated by cater- 
pillars about an inch and a quarter in length, with a yellow head, 



THE INSECT WORLD. 



277 



Fig 



the body striped with narrow black or reddish-brown hnes, ex- 
cept at the sides, where it is gray or yellowish. Near the pos- 
terior extremity is a rather prominent, humped segment entirely 
red in color. When full grown they go underground, and from 
them come, in the spring 
following, moths gray in 
color, mottled with brown, 
but the front of the body 
and a margin along the 
anterior edge of the fore- 
wings white or nearly so. 
These are called Edema 
albifrons. The body is 
rather cylindrical, heavy, 
extending somewhat be- 
yond the hind wings 
and obtusely terminated. 

Feeding exposed as these insects do, they are readily destroyed 
by the arsenites. 

One other caterpillar sometimes occurs in swarms on a great 
variety of plants, including some fruit-trees, and this is known 
as the "red-humped prominent." It is yellowish brown in 
color, pale along the sides and striped with slender black lines. 
The fourth segment is humped and of a red color like that of the 

Fig. 302. 




Edema albifrons and its larva. 




CEdemasia concinna and its larva, the " red-humped prominent 




head. There are a number of short spinous processes along the 
back, and some which are larger and more prominent on a hinder 
segment. The moth that emerges from this larva is the CEdem- 
asia co7icinna, and is of a light-brown color, the wings expand- 
ing a little more than an inch, the anterior pair dark brown along 
the inner margin and more or less gray tinged before. The 



278 



AN ECONOMIC ENTOMOLOGY, 



measures already recommended are applicable to this species, 
and in fact none of the caterpillars belonging to this family need 
ever cause serious trouble or difficulty in their control. 

Next come the CeratocampidiE , containing only a few very 
large species whose caterpillars are more or less furnished with 
horns, spines, or similar processes. The moths are sometimes 
contrastingly colored and distinguished by having the antennae 
in the male feathered for only a portion of the distance ; the ter- 
minal third of the stalk lacking the pectinations, while towards the 
base there are two branches to every joint. 

Occasionally we see a very large, green caterpillar, with black 
and red blotches, and with four very long horns, yellow at the 
base and black at the tip, on the first segments. This is an 
insect much dreaded, and known by the attractive name of " the 
hickory horned devil. ' ' The first part of the name is from the 
food plant upon which it is often found, the second from its prom- 
inent horns, and the third from its supposed evil inclinations. 
Yet the creature is absolutely harmless, incapable of inflicting the 
slightest injury upon even the most delicate subject, and it de- 
pends for protection entirely upon its formidable appearance. 
The moth resulting from it, atheroma regalis, or " regal wal- 
nut-moth," is rare and seldom seen, flying only at night and not 
much then, because, having no tongue, it does not feed. It is, 
however, rather handsome, tawny brown in color, the veins 
streaked with red and with two series of more or less distinct 
yellow blotches. It expands from three to nearly six inches, and 
is one of the largest of our night-flying moths. 

The species belonging to the genus Anisota are sometimes 
much more abundant, and occasionally become troublesome on 
oaks. I have seen acres of forest almost entirely defoliated by 
large yellow and black-striped caterpillars, with black head, two 
long, black filaments on the anterior, and numerous shorter 
black processes on the other segments. These are the ' ' orange- 
striped oak worms," which, when mature, go beneath the sur- 
face of the ground, change to brown, roughened pupae, and in 
spring appear as brown moths ; the A7iisota senatoria. The males 
are much the smaller, have the fore-wings somewhat triangular 
and pointed, a little transparent towards the middle, and with 
a clear white spot near the centre. The females are rather 



THE INSECT WORLD. 



279 



lighter in color, the white spot is much smaller, and the wings 
are not in the least transparent, but irrorated with darker, small 
spots, which give them a powdered appearance. 

On maples, especially in the more southern States, we often 
find a smaller caterpillar, which is green, with black stripes, and 
marked with little red dots. The resulting moth is known as 
the ' ' rosy Dryocampa, ' ' and has the fore-wings rose colored, 



Fig. 307. 




Dryocampa rubicunda. — a, its larva ; b, its pupa ; c, female moth : the rosy 
Dry 0 camp a. 

crossed by a broad pale-yellow band, while the hind wings are 
pale yellow, with a short rosy band behind the middle. It is 
rarely abundant enough to need attention, but when it does, the 
external feeding habit indicates the remedy at once. 

Next we reach the series of species that are silk-spinners par 
excellence in the caterpillar state. They are known in a general 
way as bombycids from the term Bo?nbyx, which was for a long 
time appHed to the "silk- worm." Among the largest of our 
Lepidoptera are the species of Attacus, which expand from four 
to eight inches, and are allied to the giants of the tropical region, 
which have a spread of wing of sometimes fully twelve inches. 
None of our species are ever numerous enough to be really 
troublesome, and they are interesting rather from the habits of 
the caterpillars, which, before changing to pupae, spin a very 



28o 



A.V ECONOMIC ENTOMOLOGY, 



large and dense cocoon of silk, in which they remain until ready 
to transform into moths. The most common of these spinners 




is the cecropia, Platysamia cecropia, the caterpillar occurring on 
a great variety of plants, including many of our fruit-trees and 



THE INSECT WORLD. 



281 



certain small fruits. It is green, and has six rather prominent 
warts on the thoracic segments, of which four are coral-red in 
color and the hinder two are yellow, sometimes with a reddish 
tinge. On the rest of the body are other tubercles which are 
furnished with little clusters of spurs and spines. The cocoon is 
sometimes spun in bushes, attached to a twig, sometimes at an 
angle of a fence, or wherever the caterpillar happens to consider 
it convenient. The resulting moth is dusky brown and powdery. 



Fig. 309. 




Caterpillar of the cecropia moth. 



the hinder margins clay-colored, a kidney-shaped dull-red spot 
with a white centre and a narrow black edging is near the 
middle of each wing, and beyond the spot is a wavy dull- red 
band, bordered internally with white. The primaries near the 
base are dull red, and near the tip is an eye-like black spot within 
a bluish-white crescent. Several other species occur, all more 
or less resembling in general appearance the cecropia, and spin- 
ning much the same kind of cocoon. 

Of a somewhat different type is the polyphemus, Telea poly- 
phemus^ which has a green caterpillar without prominent tuber- 
cles, but with little, black, wart-like processes, giving rise to 
small, stiff bristles. This feeds upon oak and a variety of other 
trees, but is rarely abundant, and when forming its cocoon spins 
up in a leaf, which later drops to the ground. This cocoon is 
oval in shape and completely closed, differing from that of 
cecropia and its nearest allies, in which it is open at one end. 



282 



A/V ECONOMIC ENTOMOLOGY. 



Fig. 310. 



The moth is dull ochre-yellow in color, more or less clouded 
with black in the middle of the wings, on each of which there 

is a transparent eye-like spot, divided 
transversely by a slender line and en- 
circled by yellow and black rings. 
Before and adjoining this spot in the 
hind wings is a large blue patch 
shading into black. 

With a very similar caterpillar and 
cocoon, the luna moth, Adias luna, 
is entirely different from the poly- 
phemus. It is of an even, bluish-green 
color, sometimes verging into yellow- 
ish, with a little eye-like spot on all 
wings, the anterior border of the fore- 
wings margined with scarlet, while the 
hind wings are each furnished with a 
long tail. 

When these caterpillars are noticed 
on a cultivated plant they can be 
easily picked off and destroyed, but 
as a rule their natural enemies serve 
to keep them reduced to compara- 
tively small numbers. These Ameri- 
can species produce a much greater 
quantity of silk, of a much stouter 
texture than the Chinese silk-worm 
proper ; but, unlike it, their thread 
cannot be reeled. It is this that makes 
it impossible to use our species suc- 
cessfully for the production of a cheap 
and strong silken fabric. 

We sometimes find on corn, clover, 
apple, and other plants or trees a 
green caterpillar, with a brown stripe edged with white on each 
side of the body, covered also with little processes, from which 
arise clusters of prickly spines. These have urticating proper- 
ties, so that if the larvae are carelessly handled a certain amount of 
irritation may arise, though much less than is the case with the 




Cocoon of the cecropia moth. 



THE IXSECT WORLD. 



283 



slug-like caterpillars previously described. They become rather 
more than two inches in length, spin a thin, irregular, and some- 




what parchment-like cocoon, and emerge in due time as " io" 
moths, — Automeris (Hyperchirid) io. The male is deep yellow, 



284 



AN ECONOMIC ENTOMOLOGY. 



the primaries only a little banded with narrow lines, the wings 
reddish on the interior margin, with a narrow band of the same 

color outwardly. On the 
Fig. 312. middle of the hind wing is a 

large, round, blue spot, with 
a broad black border and 
a central white dash. In 
the female the primaries are 
purple-brown, the transverse 
lines gray and much more 
prominent, and there is a 
somewhat dusky, pale-mar- 
gined, nearly kidney-shaped 
discal spot. The hind wings 
are essentially like those of 
the male, and altogether this 
sex is larger than its com- 
panion. 

The only other of the silk- 
spinners to which attention 
need be called here are the 
species of Clisiocampa, which are interesting from the fact that 
most of them live in colonies and spin a tent of silk on the trees 

Fig. 313. 




Larva of io moth. 






Automer'ts io, female. 



attacked by them, whence they are called "tent-caterpillars." 
Our common species in the East is C. a?nerica7ia, found in apple 



THE INSECT WORLD. 



orchards very early in the spring. During the winter we often 
find on the small twigs of the apple an incomplete belt of a 
very dark brown, wax- 
like material. If we 314- 
examine this carefully 
we find it to consist of 
a very large number of 
eggs soldered together, 
from which caterpillars 
hatch, sometimes be- 
fore the leaves have 
started, which at once 
spin a little web or tent 
in the nearest fork. 
Here they live in com- 
pany, moving out from 
time to time to feed 
upon the surrounding 
leaves, and increasing 
the size of their habita- 
tion as they grow. The 
* ' tents' ' form promi- 
nent and unsightly 
objects in neglected 
orchards, and are some- 
times rather unpleas- 
antly conspicuous in 
others that purport to 
be well kept. When 
full-grown the cater- 
pillars abandon the 
nest, crawl to some 
convenient shelter in 
the vicinity, and spin a 
yellow, rather thin cocoon, which becomes covered with a fine 
yellow powder. The moth is dull reddish in color, more or less 
brown-tinged, and the fore-wings have two oblique, pale stripes. 
The males are considerably smaller than the females, and as a 
rule darker in color, tending to have the wing between the lines 




The American tent-caterpillars, a and on the out- 
side of their tent near the entrance ; d, cocoon ; c, 
egg-mass of an allied species ; above all the female 
moth, Clisiocampa america?ia. 



286 



AN ECONOMIC ENTOMOLOGY. 



paler, while in the female we have, on the whole, an opposite 
tendency. In the West, other species replace the americana, 
but their habits remain essentially the same, and they may be all 
treated in the same manner. During the winter the egg-masses 
are easily seen after a little practice, and they can generally be 
reached and cut down without trouble. Early in spring the 
nests are prominent objects and easily destroyed, with the entire 
colony. Where they are out of easy reach, simply spraying the 
branches nearest to their nest will destroy them in a day or two. 
In orchards in which spraying is systematically done for other 
pests, these insects rarely get a foothold. 

The true silk- worm, Sericaria mori, though economically im- 
portant, is hardly a proper subject for this work. Its history is 
so well known, and has so many special books devoted to it, 
that it is unnecessary to go into details here. 

In the family CossidcB we have a series of very peculiar moths, 
really low in the scale of development, but formerly placed about 
here in the classification and conveniently so treated. The cater- 
pillars are all wood-borers, living from two to four years in the 
trunks or roots of trees. They are white, or with a faint red or 
yellow tinge, more or less black spotted, and with short, bristly 
hairs. The head is large and horny, usually black, and the jaws 
are stout and prominent. When full-grown they are from two 
to three inches in length, and change to a rather slender, cylin- 
drical pupa an inch to an inch and a half in length, depending 

upon the species and sex. 
319- This pupa is furnished with a 

series of spines around the 
edges of each segment and 
sometimes also with a chisel- 
Pupa of the goat-moth. l^^e protubcrauce on the head- 
case. When ready to trans- 
form, it works itself by a twisting and wriggling motion through 
the bark and for half its length out into the open, holding fast 
by the spines on the abdominal segments. The adults, known as 
"goat-moths," from a rank odor peculiar to them, have rather 
narrow, pointed wings and a long conical abdomen. The 
females are heavy fliers, and both sexes are attracted to light, 
though rarely seen otherwise. The head is small, very much 




Fig. 323. 



Fig. 315. 




THE INSECT WORLD. 



287 



retracted, and the tongue is obsolete, so that the insect is in- 
capable of feeding. None of our American species attack culti- 
vated plants or trees so as to become injurious, though in forests 




young oak timber is sometimes badly injured by the Prionoxys- 
tus robini(B. 

There has been recently introduced into the Eastern United 
States a European species known as the leopard-moth, Zeuzera 
pyrina, and this has become a pest on the shade-trees in several 
of our Eastern cities. The male moths expand a little more than 
an inch, the female over two inches, and both are white, spotted 
with black, whence the common name " leopard-moth." There 
is great difficulty in dealing with insects of this character, owing 
to their food habits. Fortunately, even in this imported form, 
the natural checks seem to prevent its doing much injury to 
orchards or country trees ; but in the cities and towns it threat- 
ens the life of the shade-trees. The only recommendation to 



288 



AA^ ECONOMIC ENTOMOLOGY. 



be made is constant watching by some man especially employed, 
who will destroy the borers just as soon as their presence is 
noticed, and who will gather the moths beneath the electric lights 
now found in most cities. Pans in which oil or some other sub- 
stance is kept to kill the insects falling into them, properly 
arranged just beneath the lights, will prove of considerable 

Fig. 321. 




The wood "leopard-moth," Zeuzera pyrina. — a, b, larva, from above and side, about 
half grown ; c, male, d, female ; e, larval burrow, showing the tendency of the full- 
grown caterpillar to girdle its food plant. 



benefit ; but it will take years of steady work to lessen the insects 
in some of our cities, and to remove them as a source of danger 
to the shade-trees. 

In the i^imAy JVochddcs, or "owlet-moths," we have a large 
number of species, and among them many that are troublesome 
to the agriculturist. The moths are, as a rule, sombre gray or 
brown, expanding when the wings are spread between one and 
three inches, averaging perhaps an inch and a half in the majority 
of cases. The fore-wings are comparatively narrow, rather short 



THE INSECT WORLD. 



289 



and stout, crossed by a series of more or less marked cremilated 
or wavy lines, and with two usually darker or paler spots in the 
discal part of the wing. Of these, that nearest to the base of 
the wing is round or nearly so, and is called the orbicular ; the 
other and larger, nearest to the outer part of the wing, is kidney- 



FiG. 322. 




Wing of an owlet-moth, with all the markings defined and named. — Right wings: 
^, basal line; /.a., transverse anterior line; m., median line or shade; t.p., transverse 
posterior line; st., sub-terminal line; t., terminal line; sm., sub-median vein; apex 
of hind wing ; o.m.^, outer margin ; i.mA, inner margin. Left wings : d.d., basal dash ; 
cl., claviform ; or., orbicular spot ; re?i., reniform spot ; ap., apical spot ; cm., costal mar- 
gin ; o.m., outer margin; i.m., inner margin; h.a., hind angle; d.s., discal spot; e.l., 
exterior line ; cw., anal angle. 

shaped, or narrow-ovate, and is called the reniform. These 
terms are frequently used in economic literature, and the spots 
are in many cases characteristic. Taken as a whole, the species 
of the Noctuid family are very much alike, and no attempt will 
be made here to distinguish them, except in the most superficial 
manner. The hind wings are usually without markings, and 
when at rest are concealed by the fore- wings, which lie overlap- 
ping and covering them, either flat on the back or roof-like, a 
little oblique. In the early part of the series we have a number 
of species with hairy caterpillars that sometimes feed on shade- 
trees. We occasionally find a rather large yellow caterpillar, 
densely clothed with soft yellowish hairs and interspersed here 
and there a pencil of much longer, black hair. This is the cater- 
pillar of Acronyda americajia, one of the "dagger-moths," so 

19 



290 



A.V EC 0X0 MIC EXTOMOLOGY. 



called from the fact that on the fore-wings there are a number of 
short black streaks crossing the transverse lines in such a way 
that the marks have a remote resemblance to a dagger, or to the 
Greek letter psi, c'-. They are all of some shade of grav, varying 
from very light ashen or nearly white to almost black ; but none 
of them are seriously injurious. 

The more typical Noctuids are rarely seen during the day. 
They hide under bark or stones, in out-houses, or wherever they 
can find shelter. Occasionally they sit brazenly upon the trunks 
of trees or branches, or openly upon stones, their colors and 
markings blending so perfectly with their surroundings that they 
are invisible, except to the trained eye ; but at night they are active 
and flv readily, many of the species being attracted to light, and 
nearly all of them to sweets : for these insects are furnished with a 
well-developed tongue and require food. When the moths are 
examined in the dark, their eyes are seen to glow with a deep 
phosphorescence that is quite startling at first sight. The ento- 
mologist makes use of their sweet tooth by what is known as 
''baiting" or " sugaring,"' placing a mixture of molasses, beer, 
and rum in patches upon trees, fence-posts, or even stones, and 
visiting them after dark with a lantern. The moths are often 
attracted in great numbers to these lures, and many species not 
otherwise obtainable are thus added to our collections. Many of 
their caterpillars are known as "cut-worms," and when full- 
grown average from an inch to an inch and a half, sometimes 
reaching, but rarely exceeding, two inches in length. They are 
naked, obscurely colored, usually varying from dirty gray to 
dirty yellow-brown, generally with feebly-marked longitudinal 
lines, and rarely with well-marked black spots. They hide 
during the day a little below the surface of the ground at the 
base of the plants upon which they feed, and during the night 
come out to feed upon Avhatever vegetation they can find. Nor- 
mally, the female moth lays her eggs in grass land after mid- 
summer, but sometimes weedy fields are selected, or partly 
overgrown orchards, or, in fact, any location with a sufficient 
quantity of low vegetation to support the caterpillars. They are 
rarely laid directly on or in the ground, but may be deposited on 
trees, stones, or leaves. When the lar^-ae hatch, late in summer 
or early in fall, they feed upon whatever vegetation is in the 



Fig. 331. 




Cut-worms and owlet-moths.— Fig. 324, Agrotis ypsilon and its larva, the "greasy 
cut-worm." Fig. 325, larva of Noctua clandestina, the clandestine cut-worm. Fig. 326, 
-Peridroma saucia. Fig. 327, eggs of the same, a single example enlarged at a. Fig. 
328, its larva, the variegated cut-worm. Fig. 329, Carneades messoria and its larva, the 
dark-sided cut-worm. Fig. 330, the climbing cut-worm, larva of Carneades scandens. 
Fig. 331, Hadena devastatrix and its larva, the glassy cut-worm. 

291 



292 



AN ECONOMIC ENTOMOLOGY. 



fields, being by no means nice in their choice, and only requiring 
that it be juicy and that there be plenty of it. They become 
about half-grown before winter sets in, and hibernate among the 
roots of the plants upon which they have been feeding, or under 
stones, logs, or other cover. In this condition they remain until 
the spring following, and then manifest quite a variety of habits. 
In orchards some of the species develop a climbing tendency, 
and make their way upon trees or shrubs to cut off the young- 
shoots and buds. These have been termed ' ' climbing cut- 
worms,'' but as a matter of fact a number of species develop 
this habit when the larvae are in the proper location. Where 
there is an abundance of low plants, these are eaten off at about 
the surface of the ground, and the cut-worms fill themselves 
until they seem almost ready to burst with the juicy tissue. 
Where sod land has become badly infested by them, and is 
ploughed and planted in spring, very frequently everything is 
eaten off as fast as it shows above the surface. In some cases, 
where they are very numerous, it is absolutely impossible to 
obtain a stand of corn, and the crop must be abandoned in favor 
of some other which the insects do not attack, although this 
apparent exemption is frequently due to the fact that the insects 
have wandered off, or have become full-grown and changed to 
pupae. This change usually occurs some time during the latter 
part of June, or in July, and little complaint of injury from cut- 
worms is heard after that period. The moths do not make their 
appearance until late in August or September, and lay their eggs 
during the latter month. Some species are double-brooded, and 
may be found even later than this, until November or even 
December. This, be it understood, is only a very generalized 
history of one group, and is not intended to apply even to all of 
the genera whose larvae are cut-worms ; but for all practical pur- 
poses the injurious species may be assumed to have habits 
similar to those just described. The reason cut-worms are so 
injurious is that the abundance of plants in an overgrown field 
where the eggs are laid is replaced by a very small quantity set 
out by the farmer for his purposes. The result is that the cut- 
worms, comparatively moderate in number in the first place, 
become exceedingly plentiful, and destroy the cultivated plants 
about as fast as they make their appearance or are set out. In 



THE INSECT WORLD. 



293 



regions where cut-worms are known to be troublesome it is a 
good plan to fall-plough sod-land as early in the season as conven- 
ient. This will avoid egg-laying by the late moths, and cater- 
pillars that have already hatched will be compelled to make their 
way to points where food is more plentiful, leaving the ploughed 
field free. It is a good plan also to put on at this time all the 
potash that is to be used on the crop in the form of kainit. 
The insects do not like this material on account of the chloride 
it contains, and many of them will be killed, while most of the 
others will be driven off. The potash is not lost, but will be 
as effective as if applied the season following. The field can be 
treated in spring as needed by the special crop, and will then be 
practically free from cut worms. If this method is not feasible 
for any reason, the cut-worms can be trapped by spreading on 
the surface of the ground, after it has been prepared, little heaps 
of poisoned vegetation, — for instance, clover; but any succulent 
plant will answer the purpose as well. The best way is to thor- 
oughly spray a patch of clover or other vegetation with one of 
the arsenites, one pound to fifty gallons of water, then mow it 
close to the ground, and spread in little heaps all over the field. 
The cut-worms, finding nothing else to feed upon, will eat this 
poisonous bait, and long before the corn or potatoes come up the 
field will be entirely cleared. On plants like sweet potatoes, 
cabbages, or tomatoes, that are set out, protection can be secured 
by putting at the base of each plant a tablespoonful of poisoned 
bran, using bran at the rate of fifty pounds to one pound of 
Paris green. This should be thoroughly mixed dry, then water, 
just a little sweetened with sugar, should be added until the 
whole is thoroughly wet but not sloppy. This mixture is ex- 
ceedingly attractive to cut-worms, being preferred to plants in 
all the instances that have come under my notice. It will take 
about ten pounds to an acre of potatoes as ordinarily planted, 
and perfect protection can thus be secured. For one or two 
- nights, perhaps, a few plants may be cut, but after that, except 
in rare instances, no further trace of the insects will be noticed. 
As against the climbing cut-worms a band of raupenleim or 
dendrolene will in most cases afford protection, especially if 
reinforced by a little mass of the poisoned bran at the base of 
each tree. A broad layer of fluffy cotton batting, tied at the 



294 



AN ECONOMIC ENTOMOLOGY. 



bottom and folded over to form a cone, is a good substitute for 
the raupenleim. 

Further on in the family we have a series of species which, 
with similar habits in the adult, have quite different larval char- 
acteristics. The moths themselves are different in appearance, 
becoming white or yellowish, without obvious markings, except 
irregular streakings on the veins and a series of more or less 
marked black dots. These are usually members of the genus 
Leucania, and the caterpillars have been called in general "army- 
worms, ' ' though to only one of the species can this term be prop- 
erly applied. The "army-worm," Leucania U7tipuncta, has the 
fore-wings of a rather even, dull-reddish fawn, powdered with 
fine black speckles, some of which form a transverse row of dots 



insect its specific name unipuncta. The moths fly at night, and 
are attracted to both light and sugar, forming in some seasons 
the most common of all the insects taken by the collector. The 
eggs are laid on the leaves or stems of grasses, using that term 
in its widest sense, and usually concealed. The moths favor 
rank vegetation, and the caterpillars, when they hatch, attack 
whatever is nearest at hand. When full-grown they are from 
one and a half to two inclies in length, striped with yellowish on 
a dark-gray ground. The head is yellow, with fine dark lines, 
and the insect is easily recognized when it appears in numbers. 
In ordinary seasons, though the larvae may be quite abundant, 
they are little noticed and do no particular injury ; but sometimes, 
by a combination of circumstances, the number of eggs deposited 
early becomes very great and the resulting army of larvae so 



Moth of army-worm, Leucania unipuncta, at a,- tip of ab- 
domen of female at b ; c, d, e, structural details. 




Fig. 332. 



on the veins beyond 
the middle. There 
is also a fine, ob- 
1 i q u e, blackish 
streak just below 
the apex, and at the 
end of the median 
vein is a small white 
dot, which gives 
the wing a rather 
characteristic ap- 
pearance and the 



THE INSECT WORLD. 



295 



large that they make havoc where they hatch. In this stage they 
are noticed in wheat where it is heaviest, and thence the cater- 
pillars spread in every direction. They soon become full-grown, 
go a short distance underground to change 
to mahogany-brown pupae about three-fourths 
of an inch in length, and shortly thereafter 
the moths appear. They mate at once and 
lay another batch of eggs, from which we 
have about midsummer a second army much 
larger than the first. These soon eat every- 
thing on the ground first occupied by them, 
and are then forced by hunger to begin those 
marches which have given them their com- 
mon name, "army-worm." It is an inter- 
esting, though to a farmer not a pleasant, 
sight to see the march of these insects from 
a stripped field to one that is still green and 
flourishing, and to note how quickly every- 
thing becomes covered and disappears, a sin- 
gle day sufficing to clear a large plot of every trace of vegetation. 
When full-grown these larvae in turn go underground, and now 
there is a divergence in development. Some of the pupae remain 
unchanged all winter ; some of them produce moths, and of 
these some will go into winter-quarters and hibernate, while 
others mate and lay eggs for a late brood of caterpillars, which 
becomes only partially grown. The insects may, therefore, 
winter in either the larval, pupal, or adult condition, though it is 
probable that the pupa stands the best chance of surviving. At 
all events, this explains how it is that caterpillars of all sizes may 
be found at all times, and that during the entire season moths 
may be found. In my own experience, there has not been a 
week in the collecting year when I have not taken this insect, 
while seeking better species. The remedies to be adopted are 
* almost entirely mechanical. Where the larvae are noticed at the 
first start in grain-fields or grass lands, the patches infested by 
them should be at once cut down and utterly destroyed by 
fire, and with them, of course, the larvae. The work must be 
done thoroughly, because otherwise the caterpillars will simply 
crawl to adjacent plots, and the labor is wasted. The thorough 




296 



A.Y ECONOMIC EXTOMOLOGY. 



application of an arsenical spray in the infested patch and imme- 
diately surrounding it is beneficial in some cases, but there is the 
practical difiiculty that grasses do not hold a water spray easily. 
Using soapsuds instead of pure water will overcome this, how- 
ever. If the insects become abundant enough to start on a 
march, a narrow strip can be ploughed in its line, harrowed and 
rolled, and then the roller can be kept going, crushing the insects 
as they come upon it. Or a very strong kerosene emulsion may 
be sprayed upon the caterpillars as they advance, and upon the 
fields that they are leaving. There will be no vegetation that 
need be considered, and therefore the mixture need be diluted 
five times only, which will be eftective even against the nearly 
full-grown larv^. It would seem that following one army of 
caterpillars we would have next year a still more destructive in- 
vasion, but such is not usually the case. Fungus and other dis- 
eases appear and decimate their ranks, their enemies increase 
rapidly after the first large brood, and the result is that normal 
numbers only survive, unless the conditions which favor their 
increase one year continue also the next. As the land becomes 
more cut up and cultivated, the danger from this insect is 
correspondingly lessened, and where a reasonable amount of 
promptness is displayed on its first appearance no wide-spread 
injury need be anticipated. Everything depends upon the 
promptness and thoroughness with which early measures are 
adopted and carried out, and all delays will pro^-e costly. 

A near relative of the true " army-worm" is the insect known 
as the "wheat-head army-worm," Leiccania albilinea. This is 
a rather brighter larva, also striped with yellow, never becoming 
quite as large as its ally, and peculiar in the habit of eating the 
grain or seed of wheat, rye, and other grasses. There are two 
broods of this insect also during the year, but that which does 
the injury makes its appearance in the nearly full-grown larval 
condition just when the grain is ready to ripen. At this time, 
when sufficiently numerous, their injuries to the crop are severe, 
because a single caterpillar may in a few minutes practically de- 
stroy the value of an entire head of wheat. The ears become 
rao-Q-ed and the surface of the soil becomes littered like a barn 
floor after threshing. The moths from which these insects are 
derived expand a little more than an inch, and are of a rather 



THE INSECT WORLD. 



Fig. 334. 



pale clay-yellow, with a narrow, silver-gray margin to the outer 
edge of the fore-wing. There is also a dusky stripe through 
its centre, surmounted by a white 
streak, which gives the specific 
name albilinea, or "white lined." 
Practical measures against this in- 
sect are difiicult. Where the stage 
of the grain warrants it in any way, 
the best thing is to cut it at once. 
This will save further injury, and the 
insects will distribute themselves to 
localities where their mischief will 
not count so heavily. As with the 
previous species, increase is depend- 
ent upon conditions which we do 
not entirely understand, and here 
also the parasites ordinarily obtain 
control before the year is out. 

The wandering habit is somewhat 
developed in this species as well, 
and frequently they start in grass 
lands and emigrate to adjacent 
grain-fields when the wheat-heads 
are well advanced. 

An insect somewhat similar in 
appearance in the caterpillar stage is 
the "fall army-worm," Laphygma 
frugiperda. It is smaller, however, 
the head dark with a prominent, 
white, V-mark, while the lines are 
different and the body is covered 
with rather well marked black tuber- 
cles, giving rise to short, stiff, black 
hair. The creature is a general 
feeder, and appears in greatest num- 
bers late in the season in fields of 
dense vegetation of almost any kind. In general habits it does 
not differ much from the species already described, and, like 
them, it goes underground to pupate. There are always two, 




The wheat-head army-worm.— 
a, a, eating out a head of grain ; b, 
eggs under a leaf sheath ; enlarged 
at c, d ; the moth, Leucania albilinea, 
surmounting all. 



298 



A.V ECONOMIC ENTOMOLOGY. 



and sometimes three or more broods in the course of the year, 
and in favorable seasons these become successively more numer- 
ous, so that the fall brood proves the most troublesome. These 
favorable seasons, however, do not often occur, particularly in 
the Eastern United States, and here climatic influences or other 
natural conditions reach the insects during the winter, so that in 
the spring following only a normal number survive. Cultivating 
land in crops which admit of fall ploughing is best adapted to 



Fig. 335. j^iG. 336. 




The fall army-worm.— 5, its Laphygma frugiperda and its 

head ; c, d, its body segments variations, 
enlarged. 



avoid injury, and a frequent rotation will prevent them from be- 
coming numerous enough to be destructive at any time. The 
arsenites can be employed, of course, for the protection of crops 
that admit of being sprayed. Wheat-flelds badly infested in fall 
are not necessarily ruined or even much injured, because wheat 
will stand cutting down almost to the ground during the latter 
part of the season, and will yet come up vigorous and in good 
condition the spring following. The moth that produces this 
caterpillar is a modest, gray creature, expanding hardly more 
than an inch, and the hind wings are pure white and semi-trans- 
parent. It is a variable species, and ranges from an almost uni- 
form gray to forms in which there is a considerable admixture of 
bluish white, the ordinary lines and spots of the owlet-moths 
being also well marked. 



THE INSECT WORLD. 



299 



Fig 



We sometimes find boring in the stems of wheat, corn, pota- 
toes, and a great variety of other plants a yellowish-white cater- 
pillar with rather prominent black spots, furnished with little 
soft hairs and with a black head. This is the larva of another 
Noctuid moth, the Achatodes zecE. It sometimes does consid- 
erable, though usually temporary, injury to the infested plants, 
and is kept in check, as a rule, by its natural limitations. The 
moth which produces this caterpillar is broader winged than the 
species previously mentioned, and the primaries are of a deep, 
somewhat mottled, red-brown. The outer margin is rusty red, 
especially towards the tip of the wing, and none of the other 
markings are well defined. The species has not, in my experi- 
ence, appeared in numbers large enough to make it necessary to 
adopt remedial meas- 
ures, and this is fortu- 
nate, because from its 
method of feeding it is 
somewhat beyond our 
reach. 

Occasionally we note 
upon grape-vines a 
smooth, greenish cat- 
erpillar with broken, 
rather inconspicuous, 
lateral lines. It attains a 
length of from one and 
one-half to two inches, 
and differs from the 
other greenish cater- 
pillars of the vine by lacking all trace of either horn or eye-spot 
on the last segment. It pupates a little below the surface, and in 
due time appears as a moth which is distinctly flattened, has the 
fore-wings of a mottled, dull, smoky brown, and the hind wings 
of a dull coppery hue. It is the Pyropliila pyramidoides^ and 
may be occasionally found during the day hiding in crevices, or 
under bark, for which its flattened body adapts it unusually well. 
At night it is attracted to light, and occasionally becomes rather 
common, though rarely abundant enough to need remedial 
measures. When it does occur in numbers it is easily controlled 




Pyrophila pyramidoides and its larva. 



300 



AiV ECONOMIC ENTOMOLOGY. 



by the application of a stomach poison, the caterpillar succumb- 
ing readily to any of those in ordinary use. 

There is a series of decidedly depressed or flattened moths with 
narrow, long fore-wings, broad hind wings, a somewhat retracted 
head clothed with stift", projecting vestiture, and a neat little tuft 
on the anterior part of the thoracic collar. These belong to the 
genus Xylina, or its near alHes, and they appear late in fall, to 
hibernate as adults. In spring they reappear as soon as the 
w^eather becomes in the least warm, and moths of this kind are 



often found in maple groves while sugaring is going on. Some- 
times sap-pails are found in the morning with the surface of the 
liquid completely covered with these insects, which, taken as a 
whole, are northern, though some extend south and southwest, 
and even to the Pacific coast. One of the most common is the 
X. ante7inata, the caterpillar of which has been described by 
Riley as boring into fruits ; but it is a rare species, comparatively, 
and no marked injury is ever done. 

Now we reach a group of moths in which the caterpillars 
usually lack one pair of the false or abdominal legs, and for this 
reason are known as " semi-loopers," having somewhat the 
methods of motion found in the "span-worm," but not to so 
marked an extent. Of this series we have several more or less 
troublesome species, and the most important are the "cotton- 
worms" belonging to the genera A7iomis and Aletia, all of them 
feeding upon the leaves. The larvae are similar in appearance, 
green, more or less narrowly banded at the sides, and spotted. 



Fig. 338. 




Xylina anteiinata : a, its larva in peach ; b, adult moth. 



THE INSECT WORLD. 



301 



Fig. 339. 



The " cotton-worm" is the larva oi Aletia argillacea, about which 
many volumes have been written, and whose life history has 
been thoroughly investigated under the direction of the United 
States Entomological Commission 
and the entomologists of the United 
States Department of Agriculture. 
To one especially interested in this 
insect these elaborate reports will be 
useful and must be consulted. It 
will suffice here to say that the 
caterpillars pupate in a loose co- 
coon spun on the leaves of the 
plants, and from the dark-brown 
pupa comes a dull, tawny or clay- 
colored moth, with indistinct, dark, 
wavy, transverse lines, and a rather 
prominent leaden-white spot, more 
or less margined with black, near 
the middle of the fore-wings. There 
are several broods in the course of 
the year, but only the later ones be- 
come seriously injurious, the plant 
then being sometimes entirely de- 
foliated. A curious feature is that 
the insects probably do not spend 
the winter in our territory, but adults immigrate each year from 
more southern regions. The migrating habit is marked in the 
later broods maturing on cotton in our country, and the moths 
have been often seen in great numbers as far north as Canada. 
As the wings are closely scaled, they do not readily show the 
wear and tear of long flight, and specimens have been taken 
in the far north as fresh and bright as if hatched there. It is 
possible that under favorable circumstances the caterpillars may 
support themselves on plants other than the cotton, but we 
have no positive information of their having done so. Of late 
years the insects are much less injurious than in times past, 
largely as the result of a diversified agriculture, which has made 
it less easy for them to increase in abnormal numbers. Planters 
have also learnt that a prompt application of the arsenites when 




Cotton-worms, from 
above. 



side and 



302 



A A' ECONOMIC ENTOMOLOGY. 



the larvae first appear is apt to lessen subsequent injury, if it does 
not prevent it entirely. The method of application now adopted 
is exceedingly simple, consisting of a moderately stout, rather 
elastic, pole, to the ends of which are attached sacks of a coarse 
ducking material containing Paris green. This pole is carried 
by a man on muleback, who rides between the rows, continually 
jarring it so that the poison sifts through the sacks upon the 



plants. It has been found that undiluted Paris green used in 
this way does not injure the foliage, while it is absolutely effective 
as against the larvae. Sometimes the pole is made long enough 
to hold four sacks, so that four rows are dusted at one time. This 
is exceedingly simple and practical, and has the advantage of re- 
quiring no expensive outfit. 

We have belonging to this series of semi-loopers a number of 
moths belonging to the genus Plusia, and most of these have 
somewhere in the middle of the fore-wing a dash, line, circlet, or 
other marking of silver or gold. Sometimes the entire surface is 
metalhc or golden, and the species, as a whole, are very hand- 
some, with the ground color in most cases velvety gray or 
brown. Bright colors or contrasting markings are rare. Several 
of the larvae attack cultivated plants, but none as frequently as 
that of P. brassiccs, the cabbage Plusia. The caterpillar is 
green, with rather indistinct lateral lines, and is readily sepa- 
rated from the butterfly larva of Pieris rapcE, because it lacks 
one pair of abdominal legs and is not at all velvety in appear- 
ance. Its fashion of humping itself" also separates it from the 
other larva, which always rests fully extended. This may be 
dealt with as has been already recommended for the other ' ' cab- 



FiG. 340. 




Aletia argillacea at rest and with wings expanded. 



THE INSECT WORLD. 



bage-worm," and as they infest the plants at about the same time 
in midsummer, one appHcation of Paris green or London purple 
will answer for both insects. 



Fig. 341. 




The cabbage Plusia, P. brassiccz.—a, larva ; b, pupa in its thin cocoon ; 
c, male adult. 

Another series of usually bright-colored, active moths that fly 
during the day, sometimes in the hottest sunshine, is the Helio- 
thini, which are usually white or yellow in color, and not infre- 
quently have a glossy or metallic lustre. Taken altogether, the 
species are not common, and are much more abundant both in 
specimens and species in the West and Southwest. But we have 
one form, abundant throughout the Eastern United States, which 
is at once the largest, least conspicuous, and most destructive of 
those belonging here, yielding little, in the injury it does, to any 
other Noctuid. It is the Heliothis ar^niger, whose caterpillar is 
locally known as the boll-worm" in the South, where it bores 
into cotton-bolls ; the " corn- worm" in the North, from its habit 
. of eating into ears of corn, and the "tomato-worm" in some of 
the Eastern States, from its habit of boring into tomatoes during 
the early part of the season. The species is one of the most 
difficult to deal with directly, from its habit of feeding concealed 
in such a way that in most cases the appHcation of arsenites is 
a practical impossibility. It has been found by experience that 



AN ECONOMIC ENTOMOLOGY. 



corn is the favorite food, and they will attack it in preference to 
everything else. This preference is utilized by planting corn in 
cotton-fields in such a way that the ears are in attractive condi- 
tion at the time when the moths would otherwise oviposit in the 
bolls. Before the caterpillars come to maturity they can be de- 
stroyed by hand in the ears, or the corn can be cut and fed to 
stock, together with the caterpillars. This is really the most 



Fig. 342. 




Heliothis armiger in all stages.— c, b, egg, enlarged ; c, larva ; d, pupa in its under- 
ground cell ; e,f, moths. 

satisfactory way of dealing with this insect in cotton-fields. By 
providing early corn for the early broods of larvae, and destroying 
it before they mature, the species can be kept down to harmless 
numbers later in the season. The adoption of a more diversified 
agriculture will have a tendency to lessen injury to the cotton, 
and if systematic fall ploughing of corn-fields be practised, it 
will soon become insignificant. There are two or three broods 
in the latitude of New Jersey and even more southwardly, while 
in its most northern range a single brood only is normal. In 
September or early October the caterpillars that mature in corn 
go underground and change to pupae, passing the winter in this 



Fig. 343. 




Work of the larva of Heliothis armiger in corn and in tomatoes. 



THE INSECT WORLD. 



condition. Early in spring, if the ground remains undisturbed, 
the moths, which are of a dull clay-yellow, with indistinct mark- 
ings on the fore-wings, and expand from one and one-half to two 
inches, make their appearance and lay eggs upon such plants as 
they cai^nd. Early tomatoes are favorites, and, following them, 
peas are infested. The caterpillars bore at first into the stems 
of the tomatoes, but always attack the fruit as soon as it has set. 
The earHest tomatoes are thus frequently ruined, and as these 
usually have the greatest market value, the actual money injury 
is out of all proportion to the quantity of fruit destroyed. Sweet 
corn is next attacked, and the earlier it is the more abundant will 
the insects be found in it. Last of all field corn is taken, and 
this remains infested until it becomes hard and glazed, the cater- 
pillars being able to make their way through and feed upon the 
perfectly ripe kernel. Fortunately, they are great cannibals, and 
where several infest a single ear of corn they fight until one alone 
remains. On tomatoes the insects cannot be satisfactorily treated, 
except by picking and destroying the infested fruit as soon as it 
is noticed, and the only practical means of keeping them in 
check is fall ploughing all corn-fields. It has been found by ex- 
periment and by practical experience that ploughing in the fall 
and breaking up the earthen cells in which the pupae rest will in 
almost every instance result in their death, and this process alone 
offers a fair opportunity for controlling the pest. 

There follow in the natural series a great number of small spe- 
cies, some of them very bright and pretty, many with interesting 
life histories, but none of practical importance from the economic 
stand-point. They are in turn followed by a series of larger 
species with broad wings and dull colors, the secondaries fre- 
quently crossed with lines much as in the primaries. The cater- 
pillars are half-loopers in most cases, and bear a very strong 
resemblance to the "span-worms." The most common of the 
species belonging here are the clover moths, Drasteria erechtea 
and D. crassiuscula, which are so nearly alike that they have 
been confused in collections, and we need not trouble to separate 
them. Both are broad-winged, dirty gray or brown in color, 
with two more or less marked blackish or brown bands on the 
fore-wings, and a series of little black dots before the apex. The 
female is much more modest in color than the male, and the 

20 



3o6 



AJV ECONOMIC ENTOMOLOGY. 



Fig. 347- 



black markings are so reduced as to be scarcely visible, except 
on careful inspection. The caterpillar, which is green and nar- 
rowly striped, feeds on clovers, and, while abundant, is not prac- 
tically harmful. 

Among the pets of the lepidopterist are the species of Catocala, 
a series of large moths with the hind wings black, or yellow and 

red banded with 
black. We have a 
great number of 
species, and while 
the hind wings are 
so prominently col- 
ored and marked, 
the fore-wings are 
mottled gray, 
brown, and black. 
They rest exposed 
during the day up- 
on the bark of trees, 
entirely invisible 
because so closely 
resembling their surroundings, the gaudy hind wings being com- 
pletely covered by the modest fore-wings. While some of the 
caterpillars feed upon cultivated plants, especially the plum, they 
are never abundant enough to attract attention. 

Last in the Noctuids we have the " snout-moths," or deltoids, 
the latter term applied from the fact that when the insects are at 
rest the outline bears somewhat a re- 
semblance to the Greek letter delta J. 
The species are recognizable without 
much trouble by the unusually long 
palpi, which in many cases point directly 
forward and form a decided snout. The 
only species that has occurred in num- 
bers justifying the term injurious is the 
Hypena humuli, the caterpillar of which 
— a slender green creature — feeds upon 
hops. Within my experience it has never been sufliciently 
troublesome to make insecticides necessary ; but should it ever 




Catocala ultronia and its larva. 



Fig. 348. 




Hypena humnH, 
moth. 



hop-vine 



THE INSECT WORLD. 



become so, there would be no trouble in protecting the plants 
by means of the arsenites. 

Now we reach the family GeometridcB , in which the larvae lack 
all save one or at most two pair of false or abdominal legs. In 
moving they first extend the body to its full length, then bring 
the posterior end close to the front legs, looping the body in 
the centre, then stretch out again and repeat the procedure, 
whereby they have gained the names ' ' span-worms, " " loopers, ' ' 
or ''measuring-worms," and, indirectly, the scientific term 
Geometridse. There is never any difficulty in recognizing the 
caterpillars, and the moths are easily known in most instances by 
their slender bodies, small heads, and very broad wings, which 
are also, as a rule, frail and thin. The hind wings are here orna- 
mented much as are the fore-wings, so that the lines of the one 
pair are often continued across the other. When at rest, the in- 
sects keep the wings extended and flat, much as specimens are 
pinned in the cabinet. We have a large number of species, but 
comparatively few of them become troublesome. 

Perhaps the best known of all are the ' ' canker-worms, ' ' larvae 
of the species of Anisop- 

teryx and Paleacrita. 349- 
These attack a consider- 
able variety of trees, and 
are especially fond of 
apple and pear, which 
are sometimes completely 
defoliated. They are 
much more troublesome 
in the New England and 
Northern States, and I 
have often seen, in Mas- 
sachusetts, orchards com- 
pletely defoliated by 
them. In New Jersey 
and southward they 
rarely become trouble- 
some. Here, as in some 

of the Bo7nbycids^ the sexes are unlike, the males being winged, 
while the females are wingless. The caterpillars, when full- 




FiG. 350. 




Fig- 349. Paleacrita vernata. — a, male ; fe- 
male ; c, d, structural details. Fig. 350, Anisop- 
teryx ponietaria.—a, male ; b, female ; c, d, e, 
structural details. 



3o8 



A A' ECONOMIC ENTOMOLOGY. 



grown, descend to the ground to pupate ; when the females 
emerge they crawl up the trunks of the trees, where they are 
fertilized by the males, and then continue their journey to the 
leaves, upon which they lay their eggs. This habit gives us 
control of the insects, for if we simply band the tree in such away 
as to prevent either the female or the young caterpillars from as- 
cending to the branches, it will be protected completely. Unless 
the female can get upon the leaves, the eggs are laid upon the 



trunk below any obstruction that it cannot pass. The young 
larvae will attempt to get to the leaves, and will, if they find an 
impassable barrier, starve to death. The best materials, all 
things considered, are " raupenleim, " or " dendrolene," prefer- 
ably the latter, as it remains viscid for the full period during 
which the insects hatch, and forms a perfect barrier beneath or 
through which no creature can crawl and live. A band six 
inches in width and a quarter of an inch or more in thickness 
over thick wTapping-paper will prove a perfect protection. Fluffy 
wool or cotton may also be employed, and the former is the most 
lasting, but less certain than the ' ' dendrolene. ' ' 

A near relative of these canker-worms is the ' ' lime-tree moth, ' ' 
Hybernia tiliaria, which also attacks a variety of trees, and has 
at times been decidedly troublesome. The application of the 
arsenites will prove a complete protection in this case ; indeed, we 
may say of all the caterpillars belonging to this family, including 
the " canker-worms," that they can be controlled by the thor- 
ough application of stomach poisons to the plants upon which 
they feed. 



Fig. 351. 




Canker-worm, larva of Paleacrita vernata. — 
a, b, egg, enlarged ; e, patch of eggs ; c, d, body 
segments of f, larva; g, pupa of female. 



a, larva of Anisoptejyx pome- 
taria; b, an egg, much enlarged ; 
c, d, body segments of larva. 



THE INSECT WORLD. 



One curious feature is that nearly all these span-worms closely 
resemble little dried twigs, branches, or even the stems of the 
leaves upon which they feed. Many of them when at rest hold 
to the twig by the hind feet only and keep the body rigidly ex- 
tended, seeming for all the world like a small process from the 

Fig. 353. 




The lime-tree moth, Hybernia tiliaria. — Larva all sizes ; winged male and wingless 

female. 

plant itself I well remember one occasion when Cymatophora 
pampinaria was excessively abundant on certain cranberry bogs 
on Cape Cod. I saw the spaces that had been defoliated and saw 
the edge of the spaces unaffected, but, look as I would, I could 
not at first see the caterpillars. It was not until a little smoke 
was started over the edge of the attacked portion that larvae were 
observed, and then it seemed as if all the little twigs and branches 
obtained life in an instant and started travelling. The insects so 



AN ECONOMIC ENTOMOLOGY. 



closely resembled the cranberry stems and twigs that even to an 
entomologist they were at first invisible. 

The balance of the Lepidoptera are classed in a general way as 
" micro," or small, although as a matter of fact many of them 
are larger than some of the ' ' macros. ' ' Yet, as a rule, the fam- 
ilies contain small, and sometimes very small, forms. 

At the head of this aggregation is placed the superfamily 
PyralididcE , which contains species of moderate size, varying 
greatly in appearance. We have one series, the Pyraustidcs, 
with slender bodies and rather thinly scaled wings. The pri- 
maries are banded, the secondaries are moderate in size, never 
larger than the fore-wings, and the colors are, as a rule, pale, 
usually a light clay-yellow, while the markings, which are wavy, 
are yellowish brown or black. The caterpillars in this series are 
nearly always green, with pale stripes and spots ; sometimes 
without any markings at all. The head is either black or yellow, 
hard and shining, and there is a hard shield of the same color as 
the head on the first thoracic segment. Most of them have the 
abdominal legs crowned with a complete circlet of spines, and by 
this character, which is an easy one to see, we can tell with al- 
most absolute certainty the caterpillar of a micro from that of 
a macro, in which the circlet of hooks is never complete, if we 
except the Hepialidcs and Cossidcs, which will not confuse us, on 
account of their great size and wood-boring habits. The pro- 
legs are complete, — that is to say, there are four pairs, — and the 



Fig. 354. 




The pickle-moth, Margaronia nitidalis, and its larva; the latter shown on a small 
cucumber which had been eaten into at b. 



insects have, therefore, no appearance of or relation to the 
loopers, or GeometiHdcB. Many, perhaps most, of the caterpillars 
are silk- spinners, and often five more or less concealed in folded 
leaves held together by a few threads, or in tubes above or under 



THE INSECT WORLD. 



ground. Occasionally quite large nests are built, and the cater- 
pillars are more or less gregarious, or live together in colonies. 
One of the injurious species is Margaronia nitidalis, quite a 
pretty brown-and-yellow insect called the "pickle-moth," be- 
cause the caterpillar has the habit of feeding on the cucumber, 
boring into and destroying it when about half-grown. It is more 
common in the Western States, and no satisfactory recommenda- 
tions for its control have yet been made. 

The great majority of the caterpillars live upon low herbage 
generally, rarely in numbers sufficient to cause perceptible injury, 
and most of the species are classified under the genus Pyrausta. 
We frequently notice, in passing through patches of ferns, that the 
leaves, before they become entirely unfolded, are spun up and 
held undeveloped. If we look closely we find a typical Pyralid 
caterpillar, which is easily observed and bred, pupating in the 
web itself, while the resulting moth is typical of this genus. 

The most troublesome species is the "garden web-worm," 
Loxostege similalis^ or, as it used to be called, Eurycreon ran- 
talis, and this is a great pest on vegetables of all kinds, seeming 
indifferent to the character of its food and spinning its small web 
everywhere on the plants. 
It extends over most of 
the United States, and 
has been more or less 
injurious in almost every 
section ; but, like many 
others, it seems to be 
troublesome a year or 
two and then escapes 
notice for several years 
thereafter. So far we 
have not been able to 
make out a regular peri- 
- odicity, and the remedy is Paris green or one of the other arse- 
nites where it can be practically applied. The insecticide is 
sometimes a little slow to act because the insects are more or 
less sheltered, and it is only when they feed outside their web 
that they risk being poisoned. In some cases the kerosene emul- 
sion is useful, and acts more promptly because of its ability 



Fig- 355- 




The "garden web-worm," Loxostege similalis; 
— a, larva; b, c, single segments of same; d, 



312 



AN ECONOMIC ENTOMOLOGY. 



to penetrate the webs and come into direct contact with the 
larvae. 

Sometimes insects of this series are not confined to green 
vegetation, as in the case of the "clover-hay worm," Asopia 
costalis, which attacks the dry or partially dry product, webbing 



will readily destroy the larvae. As against the "clover-hay 
worm," nothing is better than to feed up clean from year to year. 
Never put new hay upon old, and if stacked outside, lay upon 
rails so as to get ventilation underneath. Salting the first two or 
three feet has also been recommended, and will probably be 
effective. 

In the PhycitincB there are many sombre-colored little moths, 
usually of some gray tint, with rather narrow fore and broad 
hind wings. The insects rest with the wings closely folded 
around the body, the head a little elevated, and the palpi project- 
ing forward, giving them rather an impertinent appearance. The 
caterpillars are largely internal feeders, attacking fruits in many 
cases, sometimes living in the stems of plants, sometimes spin- 
ning up among leaves, in rare cases feeding openly. Occasion- 
ally they make a case or sac which they carry about with them, 
and in which they are more or less protected. 

We have several more or less troublesome species that are 



The clover-hay worm, i and 2 ; its cocoon at 3 ; 
the pupa at 4 ; the moths, Asopia costalis, at 5 and 
6 ; at 7 the tubes made by the larvae. 




Fig. 356. 



it up and causing more or 
less injury. Its near ally, 
Pyralis farinalis, may be 
found in barns or bins 
where grain is carelessly 
stored, and the caterpil- 
lars make little tubes, 
formed partially of silk, 
partially of fragments of 
the grain and even of en- 
tire kernels, upon which 
they feed. Rarely, how- 
ever, are they abundant 
enough to do serious in- 
jury, and as against both 
cleanliness will go far, 
while bisulphide of carbon 



THE INSECT WORLD. 



rather difficult to deal with. One of these is the Mineola vaccinii, 
or " cranberry-fruit worm," which lives in the berry itself, feed- 
ing in the seed-capsule, causing the fruit to redden up prema- 
turely, and then to dry and shrivel on the vine. A single 
caterpillar may eat into every berry upon a fruit stem in the 
course of its existence, then 
descends to the ground, and 
among the leaves and rub- 
bish spins a tough little co- 
coon in which the pupa 
winters safely, even if cov- 
ered by water. The eggs 
are laid about the middle of 
July, singly, on the berries 
where the blossoms have 
dropped off, under one of 
the little triangular flaps. 

Once the lar\^« are in the «, cranberry on which (^-.c) the eggs are laid; 
. . r ^' '^^'^'3^ ; ^'/> pupa and its tip ; g, cocoon ; h, 

berries there is no way 01 moth, 
getting at them, and, practi- 
cally, the only method of reducing their numbers is to pick the 
berries as early as may be, being careful to get in all that are 
infested. By sorting promptly these can be destroyed before 
the larvae leave them, lessening greatly the number of moths for 
the following year. The insect is much more troublesome in 
New England than in New Jersey or in the northwestern marshes. 

Nearly allied, but with totally different habits, is the Mineola 
indiginella, or "rascal apple-leaf crumpler," so called from its 
habit of making irregular, crumpled cases on the apple leaves 
upon which the insect feeds. It is rather easily reached, where it 
becomes troublesome, by the arsenical sprays, and in orchards 
where spraying is generally practised it is incidentally destroyed. 
Many other of these little species are found on our cultivated 
crops, but, as a rule, in such small numbers as to be hardly no- 
ticeable, and only occasionally a species becomes locally injurious. 

One of the largest of our Eastern species is the Melitara pro- 
denialis, which feeds inside the leaves of the prickly pear or 
common cactus of the sandy regions south of Long Island, while 
its near ally, M. dentata, is found in an allied cactus in Kansas 



Fig. 357. 




Cranberry-fruit worm, Mineola vaccinii. — 



314 



AN ECONOMIC ENTOMOLOGY. 



Fig. 360. 




Fig. 358. 




Fig. 360, the Mediterranean flour-moth, Ephestia kuhniella.—a, larva ; b, pupa ; c,f, adult 
with wings spread and at rest ; wing of a variety ; d, e, h, i, structural details. Fig. 358, 
Melitara prodenialis. — a, larva ; b, c, d, details of same ; e, cocoon ; y, pupa ; moth. Fig. 
1 361, the bee-moth, Galleria melonella. — a, larva; b, cocoon ; c, pupa ; d, e, moths. 



THE INSECT WORLD. 



and the Western plains generally. This caterpillar, at first sight, 
resembles one of the Noctuids very closely, and is of a beautiful, 
quite unusual, bluish tint. The moth expands nearly two inches, 
and is, perhaps, the largest of those belonging here. It has the 
peculiar habit of laying its eggs one upon the other in a pile 
which mimics the spines on the cactus leaves ; so, unless carefully 
sought for, they are easily overlooked. We find also in this 
group of variable habits a species that is carnivorous, LcBtilia 



Fig. 359. 




An egg-stack of Melitara prodetiialis. —Smglo. eggs shown at c. 



coccidivora, which, as its name indicates, feeds upon scale insects. 
Unfortunately, it is altogether too rare to be of any practical use, 
and is simply a curiosity, the carnivorous tendency in the Lepi- 
doptera being extremely rare. 

Ephestia kuhniella is another troublesome species, commonly 
known as the "Mediterranean flour-moth." It is sometimes 
abundant in barns and mills, and, especially in the latter, may do 
much injury. Great complaint has been made during the few 
years last past, the insects seeming to become more abundant 
and to cover an increasing portion of our territory. Cleanliness, 
of course, is primarily to be enforced ; but where they are 
abundant enough to make it important, the insects can be cleared 
out by using bisulphide of carbon. All the rooms should be 
tightly closed overnight, and enough bisulphide evaporated to 
fill every nook and cranny with the poisonous fumes. In a 
badly infested establishment a second application may be neces- 
sary in some cases, but in most instances one has proved effectual. 



3i6 



AN ECONOMIC ENTOMOLOGY. 



A very curious species is the Galleria melonella^ or ' ' bee- 
moth," which infests beehives and feeds upon wax. A brood 
of these caterpillars sometimes invade a hive and bore into the 
wax out of sight of the bees, frequently demoralizing them to 
such an extent that they abandon their home, seeming unable to 
find a way of dealing with this kind of enemy. In the recent 
types of hives there is little opportunity for these pests to estab- 
lish themselves, and if the bee-keeper is on the alert, he will at 
once perceive any such invasion. It is easy then, by transferring 
and cleaning out the infested frames, to save the swarm. The 
moths are rather curious creatures, mottled and streaked on the 
fore-wings, the outer margins of which are also a little excavated. 

Under the general term Crambids we may describe a series of 
species with slender body, narrow, rather squarely cut off fore- 
wings, and broad hind wings. When at rest the wings are rolled 



Fig. 362. 




Crambus vulvivagellus. — a, larva ; b, over-, and c, underground tube and cocoon ; d, e, 
f, moths with wings spread and at rest ; g, an egg much enlarged. 

Up or folded closely, giving the insect a little the appearance of a 
tiny cylinder. The head is small, not at all retracted, and usually 
furnished with very long palpi that project straight out like a 
snout ; as a whole, resembling somewhat one of the groups of the 
deltoid Noctuids. The fore-wings are generally white or yellow- 
ish, quite frequently streaked or spotted with silver and gold ; 



THE INSECT WORLD. 



but, of course, as in other groups, we have modest species in 
which gray predominates, and where the longitudinal markings 
are rather in the form of black Hues or streaks. The majority of 
the species belong to the old genus Crm7ibus, and a number of 
them are injurious in grass lands, where the caterpillars are 
known as ' ' root web-worms. " As in many other cases, it is not 
so much the grass that is injured as the corn crop which follows 
it, and, therefore, we usually find them injurious in proportion 
to the length of time that a field has been in grass before being 
ploughed for corn. Usually the moths appear quite early in spring, 
and the eggs are laid in grass some time in May, loosely attached 
to blade or stem, or sometimes simply dropped on the ground. 
The larvae, when they begin feeding, make a loose web or tube 
of silk, sometimes on the surface, sometimes a little below it. 
Occasionally they feed upon the roots, sometimes on the stalk, 
and often they enter and bore into the plant itself If an infested 
grass-plot is ploughed after eggs have been laid or after the cater- 
pillars have hatched, such of them as survive attack the corn, if 
that is the crop planted. Occasionally entire fields are destroyed, 
while quite frequently much damage is done. The moths make 
their second appearance a little after midsummer, and are never 
troublesome then, because the eggs are laid in grass lands, where 
the caterpillars, though abundant, are not noticed. From this 
general life history it will be seen that fields can be kept clear by 
fall ploughing, or by turning the sod very early in spring before the 
moths have made their appearance or had an opportunity to de- 
posit eggs. Bare ground will not become infested, nor, usually, 
will a corn-field if there is any grass in the vicinity. Where 
injury is caused on lands ploughed late, I have found that certain 
commercial fertilizers exercise a beneficial effect ; in fields fertil- 
ized with potash in the form of kainit or muriate, the exemption 
may be complete, while in adjacent plots fertilized with barn- 
yard manure, injury may be serious. It is also possible to pre- 
vent trouble by planting some other crop between sod and corn, 
where such rotation can be profitably adopted. 

In the genera Diatrcsa and Chilo we have insects resembling 
those already described, but rather larger, with often more slen- 
der pointed wings and longer palpi and abdomen. Here the 
larvae are usually borers, some in corn, some in sugar-cane, and 



AN ECONOMIC ENTOMOLOGY. 



Fig. 366. 



some in other plants. As with all other borers, there is difficulty 
in reaching them directly, and besides destroying infested plants, 
nothing really satisfactory has been proposed. Diatma saccha- 
ralis bores into sugar-cane and into corn, often doing much in- 
jury to the latter crop in the States south of the Potomac. 
There are two or more broods, depending on latitude, the last 
remaining through the winter in the larval stage in the corn- 
stalks. We have thus an obvious remedy in removing and 
destroying or using these up completely before the spring follow- 
ing. In sugar-cane the matter is not so simple ; but by burning 
tops, cutting close to the surface, and planting in fall from sound 
canes only, the injury can be at least much reduced if not en- 
tirely avoided. It is another in- 
stance where an intelligent farm 
practice will answer every pur- 
pose, without a resort to insecti- 
cides of any kind. Mats, both 
flat and round, are especially to be 
avoided for affected canes. 

An interesting little family is 
the PterophoridcB, peculiar in 
having the wings split into feath- 
ers or plumes. Occasionally the 
primaries have only a cleft that 
does not extend beyond the mid- 
dle, but sometimes they are split 
for the full length. The hind 
wings may be divided into from 
four to six feathers, the insects 
being therefore termed ' ' plume 
moths, " or ' * feather-wing moths. ' ' 
As a whole, few of the species are 
common, and I am acquainted 
with only one that is in any way 
injurious, — the "grape plume," 
The caterpillar of this is pale yel- 
lowish or nearly white, with little tubercles, from which rise tufts 
of pale hair similar to those of some Arctiids, or " woolly bears." 
It lives in the tips of young shoots of grape, webbing up the 




The grape plume, Oxyptilus peris- 
celidactylus. — a, larvae in a spun -up 
tip ; b, pupa ; c, its breast projection ; 
d, moth ; e, a single segment of larva. 

Oxyptilus periscelidadylus. 



THE INSECT WORLD. 



terminal leaves soon after growth has started, and eating out the 
heart. It would seem thus as if considerable injury might be 
caused, but really this is not so, because in most cases they do 
not attack the shoots until the buds have become freed, — that 
is to say, the shoots are attacked above the flower cluster, so 
that no injury is done to the resulting crop. When the insects 
disappear, which they do quite early, the shoot simply sends out 
a new spur from the last leaf, and the effect of their presence is 
scarcely noticed. Practically, there is no method of checking 
their increase, except by picking off the infested tips or crushing 
the caterpillars within the webbed leaves. 

We have another series of families grouped under the Tortri- 
cids, sometimes called "bell-moths," from their peculiar appear- 
ance when at rest, but more commonly " leaf- rollers," from the 
quite usual larval habit of folding or rolling up the edges of 
leaves. We have a number of troublesome insects in this series, 
and some of them are not easy to deal with. The moths are 
quite easily recognized by their broad, short fore-wings, forming a 



Fig. 367. 




Teras mimita.—a, larva; b, pupa; c, Rhopobota vacciniana. 

moth ; d, case made on apple-leaf. 



more or less obvious shoulder on the front margin. These wings 
are held roof-like, the edges overlapping only a little at the 
middle of the back, and completely conceal the moderate or 
small hind wings. Their colors are frequently bright and con- 
trasting, while in other cases they are uniform and sombre, the 
entire insect inconspicuous and unattractive. One of the com- 
mon species is Teras minuta, whose larva attacks, among others, 



320 



AN ECONOMIC ENTOMOLOGY. 



apples and cranberries : in apples simply feeding upon the leaves 
in a little case, but on cranberries often becoming seriously injuri- 
ous by spinning up and eating the tips of the growing shoots. It 
also feeds on huckleberry and allied plants, and from them goes 
to cultivated cranberry bogs. It is there known as the ' ' fire- 
worm," and it is distinguished from Rhopobota vacciniana, 
another caterpillar with the same habits, by having a yellow in- 
stead of a black head. Both these insects have similar larval 
habits, but the Rhopobota has only two broods, and hibernates in 
the egg stage, while the Teras has three, and hibernates as an 
adult. There is a curious alternation of generations in this in- 
sect, the summer broods being yellow or orange, while the moths 
that hatch in the fall and hibernate are uniformly slate-gray. 
Cultivated cranberry bogs are covered with water during the 
winter, and the moths cannot hibernate on them ; so, as they lay 
their eggs quite early in spring, if the bogs are kept covered 
until all other vegetation has started, they oviposit elsewhere, 
leaving the bogs free. Therefore, holding the water late, say 
until at least the middle of May, is usually a fairly complete pro- 
tection. The Rhopobota lays 
its eggs upon the cranberry 
plants late in summer. They 
remain unaffected by the 
water with which the bog is 
covered until spring, then 
hatch, and the larvae spin up 
the tips precisely as in the case 
of the Teras, the moths com- 
ing to maturity early in July. 
Eggs for a second brood are 
then laid, and these are some- 
times sufficient in number to 
sweep entire bogs, giving them the appearance of having been 
burned over, wherefore this insect has also been called * * fire- 
worm." As against this species, late holding the water is not so 
effectual, because it must be kept on until sufficiently warm to 
induce the eggs to hatch, the young larvae dying as soon as they 
break the egg-shell, or stifling before they are really born. The 
method is feasible on a flat boQf where water can be drawn down 




Cranberry leaf with eggs of Rhopobota, and 
a spray spun up at tip by the larva. 



THE INSECT WORLD. 



321 



so as to warm up rapidly, but there is danger in holding too long, 
because if the plants start under water, as they sometimes do, the 
crop is ruined. Occasionally, however, it pays to lose a crop 
in whole or in part, to free the bogs completely of this insect, as 
they will then remain practically safe for several years in succes- 
sion. Where water is abundant and the bogs can be readily 
reflowed, the practice of the present day is to draw the water 
early to induce an early hatching of the insects, and as soon as 
the larvae generally appear, reflow, leaving on the water at 
least twenty-four hours. This will not hurt the plants at that 
period of their growth, and will kill every caterpillar upon the 
bog. The effect depends largely upon the care with which it has 
been done and upon the judgment exercised as to the proper 
time. It should be de- 
layed until the great ma- Fig. 370. 
jority of the eggs have 
hatched, but should not 
be delayed so as to run the 
risk of injuring the plants. 

In the genus Caccecia 
we have several injurious 
species, and none more an- 
noying than C. rosaceajia. 
This attacks a great va- 
riety of plants, but it is 

most troublesome on roses, spinning and folding leaves and buds 
and so destroying the flowers. These larvae are not easily dealt 
with, but spraying the plants with pyrethrum or kerosene emul- 
sion as soon as the first signs of injury are observed will generally 
serve to keep them down. On a small scale they may be con- 
trolled by compressing the spun-up leaves and killing the cater- 
pillar in its home. 

Some of the species live in communities, making a nest or 
web, and such is the Caccecia fervidana, the caterpillar of which 
lives on oak, and spins up the shoots of young trees or the tips 
of the branches of older ones. In some cases the nests become 
from three to six inches in diameter, and when the caterpillars 
have reached their full growth they pupate within it, wriggling 
out through the silken covering when ready to emerge as moths, 




Rose leaf-roller, Caccecia rosaceana. — Larva, 
pupa, and adult. 



322 



AN ECONOMIC ENTOMOLOGY. 



and leaving the empty pupa cases projecting all around. Some 
species are occasionally so numerous that the nests constructed 
by them become enormous, — four or five feet in height, and 
covering young trees entirely. This and other species having 
the same habit can be dealt with by early spraying, or, when 
feasible, by picking off the webbed leaves or shoots. 

The best known of all belonging to this family is the ' ' codling 
moth," Carpocapsa po7no7ieila, and there is no insect, except possi- 
bly the ' ' plum curculio," that has done more injury to our orchard- 
ists. The moth appears at about the time the apple-trees are in 

blossom, and lays a single 
egg upon the young fruit at 
the point where the blossom 
has dropped off. In a few 
days the caterpillar hatches, 
eats a little on the outside 
for a day or two, and then 
makes its way into the fruit 
itself, feeding around the 
seed-capsule or core, and 
making the well-known 
' ' worm' ' in the apple. Oc- 
casionally t^vo or more 
moths may oviposit on the 
same fruit, and this ac- 
counts for the two or more 
larvae sometimes found in 
one apple. Except in the 
northern part of the country, 
there are two broods, the 
first caterpillars becoming full-grown and leaving the apples about 
midsummer, changing very soon thereafter to moths, which lay 
the eggs for the larvae found in the ripe apples. The second 
brood does not so usually oviposit at the blossom end, but seems 
to have a preference for the point where two fruits touch, for we 
often notice that in a little bunch of apples every one is infested, 
the entrance in all cases being just at the point of contact. In any 
event, whether there is one brood or two, the caterpillars of the 
last, when full-grown, leave the apples, find a hiding-place under 




The codling moth, Carpocapsa po77ionella. — a, 
apple' cut to show borings of the larva ; b, place 
where the egg was laid and the larva started ; 
d, pupa ; larva ; /, g, moths at rest and with 
wings spread ; h, head of larva ; z, cocoon. 



THE INSECT WORLD. 



323 



a scale of bark or in a little depression, and there spin a cocoon, 
in which they remain unchanged during the winter. The change 
to the pupa takes place very early in spring, and the moths appear 
as already stated. It has been found that we are able to protect 
our trees by spraying them with one of the arsenites as soon as 
the blossoms have all dropped and the fruit is well set. At that 
time the young apples are upright, affording a favorable oppor- 
tunity for lodging the poison in the calyx cup, and here it remains 
until the larva makes its first and, if the spraying is properly done, 
its last meal. Under favorable circumstances a single spraying is 
sufficient to prevent injury, but practically two sprayings are re- 
quired at intervals of about a week, and a third if rain interferes 
to shorten this period, — that is to say, one just as soon as the 
blossoms are all off, and the second about a week or, if the 
weather remains dry, at most, ten days thereafter. This is to 
allow for the irregular hatching of the larvae, the rapid growth of 
the young fruit, and to make certain that all may be reached. It 
is here that promptness and thoroughness will tell. To be ef- 
fective the spraying must be done before the larvae hatch, and 
the mixture must be on every fruit to be protected. In dry 
weather ten days between sprayings is not too much ; in wet or 
showery weather three days may be too long. The young larva 
feeds externally for a day or two only, and unless it is then killed, 
is beyond our reach. Success is the result of keeping an un- 
broken film of poison on the flower end of each fruit until all 
eggs are hatched. One pound of Paris green or London purple 
in one hundred and fifty gallons of water is a good strength, or 
fifteen ounces of arsenate of lead in one hundred gallons. Some 
growers, however, use a mixture of double this strength and find 
it advantageous ; they spray carefully, use just enough to cover, 
and risk a little burning of the foliage. 

The last series in the order is the Tineina, or the " Tineid 
moths," comprising the smallest of the Lepidopterous insects. 
There is an enormous number of species, and we know very 
little about the great majority of them. With few exceptions, the 
insects have long, narrow wings, the primaries pointed, the sec- 
ondaries lanceolate, but their surface increased by enormously 
long fringes, which are in many cases broader than the wings 
themselves. They often have on the head a clothing of upright 



324 



A A' ECONOMIC ENTOMOLOGY. 



divergent scales, all of one height, giving somewhat the appear- 
ance of a little plush cap. In their life habits they vary much. 
Some are leaf-miners, living between the upper and under sur- 
faces, and each species eating out characteristic galleries that are 
visible as irregular brown lines or blotches. Others are case- 
bearers, making little houses of various shapes and texture, 
which they carry about with them, and in which they live, pro- 
jecting the head and anterior segments just far enough to feed. 



Fig. 373. 




Apple case-bearer, Coleophora yjialivorella. — a, larval cases; b, larva; c, pupa; 
d, adult moth. 

but retreating at the first signs of disturbance. A few feed openly, 
while others are borers in fruits, seeds, or even twigs. 

Among the best known are the "clothes moths," — little, yel- 
lowish creatures often seen flying in houses early in the evening, 
and which generally arouse excitement and resentment in the 
breast of the careful housekeeper, for she knows that her woollens 
and furs are in danger. The caterpillars feed upon animal tex- 
tiles of all kinds, and upon furs and feathers. They do not often 
attack vegetable fibre like cotton or linen. Their habit is to 
form a little flattened case of fibres from the material upon which 
they are feeding, and this is lined on the inner side with silk. In 
about three weeks the larva is full fed, changes to a pupa within 
its case, and the moth, when it emerges, leaves the empty shell 
protruding for half its length. There are several species engaged 



326 



AA^ ECONOMIC ENTOMOLOGY. 



in this pleasant occupation, but they have habits so nearly sim- 
ilar that there is no necessity for differentiating them here. As 
to remedies, plenty of air, sunshine, and beating will keep cloth- 
ing free, or, having been made free, it can be wrapped in stout 
paper in such a w^ay as to make it impossible for the moths to 
enter and to lay eggs, or for the young caterpillar to find a crev- 
ice through which to crawl. A cotton or linen sack, if the material 
is sufficiently dense, will afford almost equal protection. A 
closet or trunk in which plenty of naphthaline crystals have been 
strewn is also a safe place, and will be avoided by the moths, who 
cannot live in such an atmosphere. Where the insects get into 
carpets, they can be destroyed by saturating the infested spots 
with gasoline, as this is exceedingly penetrating and fatal to the 
insects w^herever it touches them. 

Another troublesome species is the Gelechia cereallella, or ' ' An- 
goumois grain moth. ' ' Its larva bores into the kernels of wheat, 
rye, or corn, a single grain of wheat sufficing to bring one to 
maturity, while in a grain of corn two or three, or sometimes 
even four, larvae find sufficient nourishment, though two is, per- 
haps, the rule. The insects sometimes lay their eggs upon the 
grain in the fields, and when it is cut and brought into the barn 
they continue breeding in the mow so long as it remains there. 
Corn-cribs frequently become infested, and the insects breed as 
long as the temperature remains m.ild. Where grain is threshed 
and bulked the upper layers may be infested, but the insects are 
not able to get in very far, because the moth is unable to escape 
through any heavy layer, becoming worn out and dying before 
reaching the surface. The insect is much more troublesome 
southward than it is in the north, where the cold weather checks 
breeding before it has an opportunity to do much damage ; but 
in regions where the temperature in the barns is moderate 
throughout the winter it frequently does great injury. The 
best remedy is threshing and bulking the grain as soon as pos- 
sible, covering the bins to keep out the insects. If infection is 
noticed, it can be easily checked by evaporating bisulphide of 
carbon in a dish upon the surface. The vapor is heavy and 
sinks through it to the bottom, effectually clearing out any in- 
sects that may be present. In corn-cribs the bisulphide can also 
be used, but the crib must be temporarily closed b}^ canvas or 



THE INSECT WORLD. 



327 



sheeting, so that the vapor may become effective before it escapes. 
It has been found by experiment that grain can be exposed to 
this vapor for a considerable time without losing in germinating 
qualities, but seed wheat should be, if possible, kept free from 
such insects. It should be selected early and kept in insect-tight 
vessels until needed for use. Open corn-cribs should be placed 
in such a way as to get the benefit of all the cold weather there 
is, and thus the multiplication of the insects will be checked so 
early that no serious damage will be done. 

There are other species of Tineids infesting cultivated plants, 
but few are widely distributed and at the same time injurious. 
In most cases the application of arsenites to those forms feeding 
openly upon plant tissue proves more or less satisfactory, while 
against those feeding upon stored products we can use the 
bisulphide of carbon. 



CHAPTER VIII. 

THE DIPTERA, OR FLIES. 

The term Diptera means two-winged, and members of this 
order are separable from all other insects by possessing, nor- 
mally, only a single pair of wings. These are borne by the 
middle segment of the thorax, and are, therefore, the first pair ; 
the second or hind pair are reduced to little club-like processes 
called " halteres," "poisers," or " balancers." Their function 
is supposed to be indicated by the last of these terms, — i.e., to 
aid the insect in directing its flight and maintaining its position in 
the air. The members of the order are, therefore, easily recog- 
nizable in most instances, but the reference of individual speci- 
mens to the proper place in the system is a matter of greater 
difficulty. They are mostly of moderate or small size, sometimes 
quite fragile, and the character of the wing venation, upon which 
much reliance is placed in scientific classification, is not readily 
made out, except by the special student. Yet a little patience 
will generally lead to the proper group, and the habits or life his- 
tory may then be used to determine more closely. 



328 



ECONOMIC ENTOMOLOGY. 



Before taking up the more typical forms, we may brieflv con- 
sider the Aphaniptera, or fleas, which are usuahy considered as 
flies that have lost their wings as a result of parasitic habits. 
They are small, transversely flattened creatures, usuallv brown 
in color, with small heads, piercing mouth parts, and the merest 
rudiments of wdng-pads. To replace wings, thev are furnished 
with greatly developed posterior legs fitted for jumping, and in 



Fig. 377. 




Rabbit flea, much enlarged. 



proportion to their size their leaps are wonderful. They live in 
the adult stage among the hair of warm-blooded animals, sucking 
blood, their form enabling them to move about easily in e\-en the 
thickest fur. So also the position of the spines clothing the 
body is such that every eflbrt of the insect pushes it for^-ard, 
which accounts for the difliculty in holding a specimen when 
captured. 

The larvae are whitish, small, worm-hke creatures, almost cylin- 
drical in form and with small brownish heads which bear fairly 
well developed mouth parts. They live upon partly decayed 
matter in or near the lairs of the animals upon which the adults 
feed, and the eggs are probably dropped at hap-hazard by the 
females while the host is at rest. A rug used as a bed for a dog 
or cat may be found full of eggs at almost any time during spring 



THE INSECT WORLD. 



329 



or summer, the larvae finding food in any dust or dirt near by. 
The spaces between the boards of floors are often filled with them, 
and a little pile of moist sawdust or shavings may harbor 
myriads. This led to a quite wide-spread and at one time popu- 
lar belief that under such circumstances the insects were sponta- 
neously generated. The period of development is very brief, 
and under favorable conditions a building may swarm with fleas 
in a month or two. No species of flea specifically infests man 
in this country, though the Ceratopsylhis serraticeps of the house- 
hold dog and cat often bothers him a little. In tropical and 
subtropical countries several species attack him as readily as 
they do any other warm-blooded animal. 

Where a house becomes infested, the dogs or cats, if any, 
should be washed with carboHc soap every other day to kill the 
adults on them, and if the animals be allowed to run throughout 
the house they will in a few days attract all the fleas to them- 
selves, where they can be dealt with. The sleeping rugs of the 
animals should be thoroughly beaten or shaken out-doors every 
day, and the most rigid cleanliness should be everywhere 
observed. 

Where dogs or cats are not available as traps, a liberal applica- 
tion of gasoline, following a thorough cleaning up, is the best 
remedy. It should be poured into every crevice in the floor and 
along the base-boards, and it will kill every larva and adult with 
which it comes into contact. The hquid is exceedingly inflam- 
mable, and must be used with that fact borne in mind. Pet 
animals can be cleaned by a free and frequent use of carbolated 
soaps or vasehne. 

In hot countries fleas are often serious pests, not only to man 
and his pets, but to fowls as well, young chickens being fre- 
quently killed by the great numbers clustering around their 
heads. Here the free use of carbolated vaseline is indicated to 
keep ofl" the insects and to act as an efiective healing agent. 
Cleanliness in its strictest form in the coops and houses is always 
indicated. 

Rather more serious pests are the so-called "jigger" fleas, 
species oi Sarcopsylla, or Vermipsylla, the females of which work 
their way under the skin, often of the feet of man, causing an ul- 
ceration in which the eggs and larvae develop. If the case is 



330 ECONOMIC ENTOMOLOGY. 

neglected, amputation sometimes becomes necessar^\ Where 
shoes are worn, the insects do not often succeed in reaching their 
favorite points of attack ; but if they do, a prompt use of the 
needle or knife or a rnercurial ointment will prevent trouble. A 

Fig. 378. 



' 'Jigger'' flea, 5a7^cc'/'Jr>'//a/^?;^^?/'?'^2?^^.— Female distended with eggs, from side and front. 



Fig 



moist quid of tobacco bound over the infested spot usually re- 
sults in killing the insects, so that the wound can be cleaned and 
left free to heal. 

The metamorphosis of the fleas is complete, like that of the 

true flies. 

The most obvious division among 
the true flies, for our purpose, is 
based upon the character of the an- 
tennae, or feelers. There are two 
series, those with long horns or feel- 
ers much exceeding the head, and 
those with short horns, having usu- 
ally only two or three visible seg- 
ments, one of which is often fur- 
nished with a specialized bristle, or 
' ' arista. ' ' The divisions are by no 
means sharply limited scientifically, 
but are sufhciently distinct for the 
species of economic importance. 

The Tipulidcs, or "crane-flies,'' 
is the first family of economic inter- 
est, and its members are recognizable by their resemblance to 
exaggerated mosquitoes. They are usually quite large, with 
many-jointed, slender, thread-like antennae and scarcely shorter 
maxillary palpi. The legs are abnormally long and ungainly, 




Antennae in flies. — a, tip of plu- 
mose antenna ; b, joints verticil- 
late ; c, aristate, the arista bare; 
d, arista plumose at base; e, arista 
plumose to the tip. 



THE INSECT WORLD. 



and the wings are narrow, so that the insect is awkward in ap- 
pearance, as well at rest as in its flight, which is slow and heavy. 
The flies are most frequently seen in low, rank meadows, or 
along ditches or sluggish streams, flying preferably during the 
morning and late afternoon hours. The larv^ are slender, cylin- 



FiG. 380. 




A crane-fly, Pachyrrhina species. 



drical, somewhat worm-like, of an extremely tough, leathery 
texture, and live underground on the roots of grasses, or in de- 
caying wood. In Europe they are known as "wire-worms," 
and are often seriously injurious ; but in North America none of 
the species have as yet proved very troublesome. It is probable 
that intelligent farm practice will be sufficient to control any of 
the species likely to become injurious with us. 



332 



AN ECONOMIC ENTOMOLOGY. 



To the family Culicidce belong the flies well and unfavorably 
known as mosquitoes. They are slender, long-winged, long- 
legged creatures, with a 

Fig. 381. 




Mosquito. — a, adult male ; e, joints of its 
antennae ; b, head and mouth parts of fe- 
male, from side ; f, larva, or wriggler ; g, 
pupa; all enlarged. 



small head, long antennae, and 
a long beak or proboscis. In 
the male the antenna are 
broadly feathered or plumose, 
while in the female they are 
slender and with a few lateral 
bristles only. In the males 
the piercing mouth structures 
are not well developed, and 
they are not capable of suck- 
ing blood, but in the females 
the puncturing structures are 
exceedingly eft'ective. Ex- 
amined under the microscope, 
the wings are seen to be cov- 
ered with scales along the veins. 

The larvae are commonly known as " wrigglers," and may be 
found at any time during the summer in any pool of stagnant or 
sluggish water, in water-barrels, cisterns, or even puddles ; in 
fact, wherever there is an inch or more of water persisting more 
than a week or two. They are odd-looking creatures with large 
head and thorax and a slender abdomen, bearing a short tubular 
structure on the penultimate segment, which serv^es to take in 
air from the surface of the water. When the larva is at rest it is 
suspended in the water head downward, the tip of the breathing 
tube just above the surface. When disturbed it wriggles to the 
bottom, but cannot remain long without rising to renew its supply 
of air. The larv^al life is very short, and the pupa, when formed, 
is bent almost into a semicircle, having the anterior portion 
curiously enlarged. This stage is also brief, and when the adult 
is ready to appear, the pupa rises to the surface, the skin splits, 
and the fly emerges carefully, the cast skin now serving as a boat 
until the newly-born mosquito becomes sufiflciently hardened to 
fly away, — a matter of a few minutes only. The eggs are laid in 
boat-shaped masses on the surface of the water, and float about 
until the larvae emerg-e, which they do throuo-h the lower end. 



THE INSECT WORLD. 



333 



The impregnated females live through the winter, hiding wherever 
they can find sheher, — in cellars, attics, barns, out-houses, piles 
of rubbish, hollow trees, etc. As soon as warm weather returns 
they begin to reproduce, and several broods are matured during 
the summer. 

In the larval stage the insects are scavengers, serving a good 
purpose in keeping the water in which they live pure and clean ; 
but as adults they are unmitigated nuisances, rendering some 
parts of our country almost uninhabitable. 

Where the opportunities for breeding are few, the insects can 
be checked to an extent by keeping cisterns and rain-barrels 
well covered, and by pouring on the surface of all ponds and 
puddles a small quantity of kerosene. The oil spreads in a thin 
film over the entire surface, and all larvae and pupae when they 
come to the surface to breathe are killed at once. Many females 
are also killed while attempting to oviposit. In favorably located 
regions the mosquito plague may be at least greatly lessened by 
this method. 

Where exposure to mosquito attack is unavoidable, the follow- 
ing mixture will serve to keep off the pests : 

Oil of pennyroyal i part. 

Oil of tar 2 parts. 

Olive or cottonseed oil 2 parts. 

Rub all exposed parts with this mixture, which will secure ex- 
emption for from one to two hours or longer without renewal, 
depending upon the temperature and the amount of perspira- 
tion. 

It remains only to say that, as mosquitoes sometimes occur in 
swarms in arid regions, many miles from water, it is likely that 
their larvae in some cases inhabit the soil. 

Closely resembling mosquitoes in appearance are the Chiro- 
nomidcs, which may be recognized by the naked wings and by 
having the thorax produced so as to hide the small head from 
above. The antennae are feathered in both sexes, those of the 
male strikingly plumose. To this family belong the gnats or 
midges which may sometimes be seen dancing in swarms in the 
evening only a few feet above ground, generally early in the 
year and in damp places. The larvae are mostly aquatic, and 



334 



AN ECONOMIC ENTOMOLOGY. 



never economically important. The minute species of Ceratopo- 
gon are furnished with piercing mouth parts, and are often ex- 
tremely irritating, but otherwise the adults are harmless, unfitted 
for blood-sucking. They are known as ' ' sand-flies, " " punkies, ' ' 

"gnats," "midges," and by 
Fig. 382. other names, some of which 

are applied indifferently to spe- 
cies of diverse families. 

The "fungus gnats" of the 
family MycetophilidcB are also 
small, mosquito-like creatures, 
but more compactly built, with 
shorter abdomen, stouter body 
and legs, and antennae that are 
not plumose or feathered in 
either sex. They are smoky 
or blackish in color, as a rule, 
and frequent decaying vegeta- 
ble matter or fungi, in which 
the larvae feed. The latter are 
slender, white, worm-like creat- 
ures, with a distinct black head, and usually feed together in 
considerable numbers. They sometimes develop a curious wan- 
dering habit when full-grown, marching in rope- or ribbon-like 
aggregations an inch or two wide and from six to ten inches 
in length. Some bands have been observed from four to live 
inches wide and twelve feet in length, piled up from four to six 
deep ! Ordinarily no injury is done by these insects, which are 
rather scavengers than otherwise ; but one species of Sciara 
becomes a serious pest to mushroom growers, eating into the 
plants and utterly ruining them. In fact, in many localities it 
is simply impossible to grow mushrooms after warm weather 
sets in. Measurable exemption may be secured by keeping the 
houses or cellars tightly closed and fumigating frequently with 
tobacco or pyrethrum to kill the flies. In a cellar the flies al- 
ways get to any window or other source of light, and great masses 
can be killed in such situations by a fine spray of kerosene emul- 
sion diluted ten times. 

Quite recently Mr. A. D. Hopkins, of the Virginia Experiment 




Chirononiiis species, male, enlarged. 



THE INSECT WORLD. 



335 



Station, has found a species of this family concerned in producing 
a form of potato scab in that State. He has named it Epidapus 



Fig. 383. 




Sciara tritici.—a, larva ; b, c, pupa from below and side ; d, female fly ; e, f, tips of 
female and male abdomen. 



scabei, and beheves it to be responsible for much of the injury 
usually ascribed to the germ disease. This may be locally true. 

Fig. 384. 




Epidapus scabei.—^'m^Xz'SS female and structural details. 



but I have never found any trace of the insect in New Jersey, 
though I have examined many hundreds of scabby potatoes for 



336 



AA^ ECONOMIC ENTOMOLOGY. 



Fig. 38; 




Eggs and larva of Epidapus 
scabei, much enlarged. 



that especial purpose. Fortunately, the measures used to prevent 
the scab due to the fungous disease seem to destroy the insects as 
well ; hence the method of distinguishing 
between the two is not important. 

In the family CecidomyidcE, containing 
the midges, or "gall-gnats," we find the 
most injurious species of the order. They 
are also mosquito-like in appearance, but 
usually very small, with very long an- 
tennae, which in the males are clothed on 
each joint with whorls of fine hair. The 
larvae are ovate, quite broad, and a little 
flattened, the segments well marked, and 
the apparent mouth parts formed in 
many species by a peculiar horny pro- 
cess which is known as the "breast- 
bone," from its situation. The species 
are numerous, and the larval habits and 
life histories are very diverse. In most 
cases growing vegetable tissue is the 
food, and, as a rule, a more or less marked gall-like swelling 
indicates the location of the larva. 

The most widely known species is the ' ' Hessian-fly, ' ' Cecid- 
o7nyia destructor, one of the most serious enemies of wheat, 
actually inhibiting its cultivation in some localities. The adult 
is rather large for this family, smoky brown in color, and appears 
late in the season, usually after the wheat is w^ell above ground. 
Eggs are laid on the young plants, and the larvae work their way 
into the stem at or near the surface, causing a slight gall or swell- 
ing and a deformity in plant growth. When winter sets in fall 
size has been reached, and the "flaxseed" stage is entered 
upon, — so called because of its superficial appearance, though it 
is really the brown, dry, and hardened larval skin itself. In 
spring the pupa is formed, and soon afterwards the adult appears, 
ready to oviposit again in the now rapidly growing wheat. The 
flaxseed stage is again formed low down in the stalk before har- 
vest, so that it usually remains in the stubble when the grain is 
cut. There it rests until the new wheat sprouts in fall, though 
flies may be found all summer, and it is more than likely that 



Fig. 386. 




33S 



AN ECONOMIC ENTOMOLOGY. 



certain grasses also sustain the species in the interval between 
harvest and seeding. 

The injury is done by stunting and aborting the wheat plants 
in the fall, and in dwarfing stalks in the spring or so weaken- 
ing them that they fall or ' ' lodge' ' readily, preventing thereby 
the development of the ' ' ear' ' or of the grain in it. 

Insecticide applications are hopeless, and modified farni practice 
is the only satisfactory measure within our power. Very late sow- 
ing in the fall — as late as it is safe to do so — will force the insects to 
oviposit in volunteer shoots or grasses, and the later germinating 
crop remains exempt. As far as possible, infested stubble should 
be ploughed under deeply immediately after harvest to destroy a 
large percentage of the "flaxseeds," or it should be burnt. 

Another, related pest, is the "wheat-midge," Diplosis tritici, 
which in the larval stage feeds upon the kernel of the grain, 
dwarfing it or causing its entire abortion. This larva is quite 
red in color, and the parent midges are about in June, oviposit- 
ing in the blossoms or on very young kernels. In this case 
also deep ploughing after harvest is advisable, and after threshing 
all chaff should be disposed of so as to destroy all chance of life 
for such insects as may yet be in it. 

The "clover-seed-midge," Cecidomyia leguminicola, is also a 
dangerous enemy in some localities where seed rather than hay 
or fodder is desired. The midges lay their eggs in the flowers, 
and the resulting larvae feed upon the forming seed, utterly de- 
stroying it. Where the insects are known to occur, cutting an 
early crop just when it is in full head and depending upon a sec- 
ond crop for seed is good practice. The midges oviposit in the 
flowers of the first crop, and those of later date will be practically 
exempt. The cutting can be high, so as just to include all the 
heads, which will be rapidly renewed from the vigorous stalks 
remaining. Fall ploughing infested fields is good practice, or 
ploughing under after cutting, and planting some cultivated crop 
that involves frequent stirring of the soil. The insects winter 
just below the surface among the roots, and the practice above 
suggested looks towards winter killing them. A liberal use of 
lime and kainit after the crop is off" is also good practice, and 
will kill many of the larvse then barely beneath the surface and 
not yet in their cocoons. 



THE INSECT WORLD. 



339 



The ' ' pear-midge, ' ' Diplosis pyrivora, is an imported species 
appearing with the first buds of early spring and ovipositing in 
them as soon as they begin to show white. The young larvae 
make their way to the ovary or seed-capsule of the setting fruit, 
and when this reaches the size of a nut, growth stops. The pears 
are then irregular in shape, a little knotty, and filled in the centre 
with a mass of orange-yellow larvae. In June these become full- 
grown, leave the 
pears, — which now 
crack open . and de- 
cay, — and drop to 
the ground, beneath 
the surface of which 
they pass the winter. 
The insect is es- 
pecially fond of the 
' ' Lawrence' ' va- 
riety, and where 
such can be found 
in sufficient num- 
bers, all others are 
exempt. The way in 
which this species 
can be controlled 
is by treating the 
ground beneath in- 
fested trees with a 
heavy top-dressing 
of kainit, — say one 
ton to the acre, — applied between the middle and end of June, 
Planting ' ' Lawrence' ' trees as traps and applying the above 
remedy to the soil beneath them will decidedly lessen the injury 
to the balance of the orchard, or their fruit may be gathered 
- and destroyed in May, with all the contained larvae. 

Not all the gall-midges are injurious, however. Many species 
form galls or other distortions of growth on weeds or other plants 
of no special economic interest, or in such a way as to cause no 
real injury, and a few are actually predaceous and directly bene- 
ficial. Such is the species that feeds in the Phylloxera leaf-galls 



Fig. 387. 




The pear-midge, Diplosis pyrivora.—a, female adult ; c, 
pupa ; other references are to structural details. 



140 



AX ECO XO MIC EXTOMOLGGY 



Fig 



on the grape, and not improbably other species occasionally 
found in leaf-galls are predatory upon the original producer. As 
a whole, the gall-midges are to be regarded as dangerous, and 
the measures to be adopted against them are. in almost all im- 
portant cases, modihcations of farm practice, since they are usu- 
ally beyond the reach of insecticide substances. 

This closes the series of long-horned, mosquito-hke flies, none 
of which are of direct benefit to the farmer, while not a few are 
among his most dangerous foes. As a whole, the species should 
be looked upon with suspicion and closely investigated when 
they occur in numbers great enough to attract attention. 

Quite early in the season we may see large numbers of loose- 
jointed, ungainly flies of moderate size, with long, stout legs, 
heavy body, short, stout, though many-jointed antenns, and 

often, in the female, a ridic- 
ulously small head. In 
color they are black, or 
black and yellow, or red. 
These belong to the family 
BibionidcB, sometimes 
called ' ' March-flies, ' ' from 
their early appearance ; and 
while their larvaE: are some- 
times feeders on grass roots, 
they ne\'er become eco- 
nomically important. They 
are mentioned here because 
their early appearance in 
great numbers sometimes at- 
tracts attention. They are 
often plentiful in orchards 
just when the blossoms 
open, but seem not to be 
of any serxice in pollen- 
izing. 

some localities serious pests 
"black flies" of the North- 




Bibio albi_pe?mts.—a, male 
male ; d, her head ; e, f. ^ 
details. 



:, its head ; b, fe- 
other structural 



" Black flies,"' or " gnats," are in 
to man and domestic animals. The 
ern woods and the "buttalo-" and "turkey-gnats" of the South- 
ern and Mississippi States are good examples. They are rather 



THE IXSECT WORLD. 



Fig. 389. 



undersized, chunky flies, dark in color, with the thorax well 
developed and somew^hat produced forward so as to partially 
conceal the small head from above. Though the head is small 
in proportion to the insect, the mouth parts are exceedingly 
well developed and furnished 
with a formidable array of 
lancets for puncturing and 
blood-sucking. They belong 
to the natural family Simu- 
liidce, and are distinguished, 
in addition to the peculiari- 
ties enumerated above, by 
short, broad wings, in which 
the venation is almost obso- 
lete, except along the front 
margin. 

The larvae are curious little 
creatures, living under water 
in rather swiftly flowing 
streams, clinging to rocks, 
sticks, or logs, and feeding 
upon vegetable matter. They 
are furnished with sucker-like 
structures at both extremities, 
by means of which they cling 
to their resting-place, and move from place to place, breathing 
by means of tracheal gills. 

In favorable localities these insects may develop in enormous 
numbers, and, flying in the bright light of mid-day, attack any 
warm-blooded animal that comes in their way. Such is their 
number sometimes that they completely cover the animal at- 
tacked, first rendering it frantic by the pain inflicted and soon 
after weak from the loss of blood. Eventually death ensues, 
whether the animal be a man or a mule, unless repellents are 
employed or a rapid retreat out of the infested territory is 
accomplished. 

Where the insects breed in shallow streams, the lar\^ae attached 
to stones, nothing can be done to check development, and the 
mixture already recommended for mosquitoes — viz., oil of tar, 




BufFalo-gnat. 



342 



AN ECONOMIC ENTOMOLOGY. 



Fig. 390. 




oil of pennyroyal, and sweet oil— must be resorted to for man, 
while fish oil, with an admixture of crude carbolic acid or creo- 
sote, will be found effective for animals. Smudges are often 
used where buffalo-gnats are abundant, and the 
stock soon learn that in or near the smoke ex- 
emption from attack may be secured. Where 
the water of infested streams 
is deep, undue multiplication 
is frequently chargeable to an 
accumulation of logs or other 

IIS ""^"^Mt^^^^-^ material at certain points, af- 

''^81 rf^^v^ fording suitable locations for 

^ * '""^ the development of the gnat 

larvae. In such cases much 
good may be accomplished 
and sometimes practical ex- 
emption may be secured by 
cleaning out the streams and 
thus destroying the breeding- 
places. Stationary rafts of logs 
should not be allowed, and the 
surface should be kept as free as possible of anything to which 
the larvae can attach themselves. 

The * ' horse-flies, ' ' or Tabanidcs, comprise another set of 
troublesome creatures, of medium or large size. They have 
short, broad heads, enormous eyes, and short, though many- 
jointed, feelers. The abdomen is oval, a little flattened, and the 
body is convex and powerful. The mouth parts are well 
developed, consisting of a series of five sharp-pointed lancets so 
rigid that they readily pierce the skin and draw blood almost as 
soon as they touch. These flies frequent woods or the edges of 
woodland, sometimes low meadows or marshy places, and occa- 
sionally prove serious pests to stock. They are often trouble- 
some in woody roads, because with three or four of the large 
black flies buzzing about, horses may be driven almost frantic. 
Similar species occur in great numbers along the sea-shore, 
where they are known as "green-heads." In some localities 
they are known as "deer-flies," and some are called "golden- 
eyed flies," having the eyes more or less banded or striped 



Larva of buffalo- 
gnat. 



Pupa of buffalo-gnat . 



THE INSECT WORLD. 



343 



with metallic yellow or brown. The female only has the blood- 
sucking habit, the males feeding usually upon pollen, and being, 
therefore, rarely noticed, except by the collector. The larvae 
are elongated, somewhat flattened creatures, some living in the 
soil, some in water, and some in marshes, preying upon what- 
ever comes in their way. In this stage they might possibly be 



Fig. 392. 




Horse-fly, Tabanus atratus.— a,\a.r\?L\ 3, pupa ; c, adult. 



reckoned of some benefit, did they inhabit places frequented by 
injurious insects ; but at best they are harmless, — unlike their 
parents in this as in all other respects. 

Horses driven through districts badly infested by these insects 
should be furnished with a netting, and, if it is necessary to keep 
the animals for any time exposed to attack, the fish oil and car- 
bolic acid mixture already recommended can be used to repel 
the flies. It need be applied only in such places as the animal 
cannot conveniently reach with its tail, or which is not sheltered 
by a netting. 

Somewhat resembling "horse-flies" in appearance are the 
members of the family Stratiouiyiidce , or " soldier-flies," so called 
because of their often bright bandings of green and yellow. 
They have the same general shape but rather longer antennae, 
with broader, much more flattened, abdomen. They are not 
troublesome in any stage, and are referred to simply because of 



344 



AX ECOXOMIC EXTOMOLOGY. 



their resemblance to, and to distinguish them from, the " horse- 
flies." 

Another series of large species we find among the "robber- 
flies" belonging to the family AsilidcB, and these are quite 
different in appearance from any heretofore treated. The head is 
prominent, very hairy, with rather short, several-jointed antennae, 

and with a short, stout proboscis. 
Fig. 393. which is formed for piercing. The 

body is robust, also covered with hair, 
and the abdomen is long, slender, and 
cylindrical, tapering very gradually to 
the tip. The wings are long and nar- 
row, the legs moderately long and very 
powerful, densely clothed with spines, 
while the tips of the tarsi are supplied 
with unusually long and stout claws. 
The insects are called ' ' robber-flies' ' 
from their habit of pouncing^ upon, 

An Asilid fiy.—Erax bastardi, . . . . . . .. ^ . 

larva, pupa, and adult. picrcmg, and suckmg the juices ot 
other insects in mid-air, while holding 
them with their powerful legs. We have a great varietv of 
species, some of them large and brightly colored, though the 
majority are of a sober gray, varying sometimes to reddish, 
sometimes to yellow, and only rarely becoming black, except in 
the genus Laphria. Though predaceous, the insects can hardly 
be called beneficial, because they rarely attack injurious species, 
and in some cases become themselves injurious by attacking 
bees. The late Dr. C. V. Riley records having obser^-ed a single 
species kill forty bees in one afternoon. Professor Comstock 
notes their feeding upon the cotton-worm, and undoubtedly 
they do occasionally kill injurious insects, but can scarcely be 
credited with being a factor of much importance in keeping down 
troublesome forms. They never attack man or animals, although, 
if carelessly handled, they are ready to sink their lancets into the 
flesh of their captor. The lar\'ae are also carnivorous, so far as 
known, and live in the ground or in decaying wood. 

Yet larger in size and of the same general shape are the mem- 
bers of the family MidaidcB. They are often contrastingly col- 
ored, sometimes uniformly dead black or blue, though usually 




THE INSECT WORLD. 



345 



relieved by a bright red or yellow band or similar marking. 
The wings are quite generally blackish and the antennae are 
clubbed at the tip, differing thus from the previous family. In 
fact, the species are so peculiar that, having been once seen, they 
can scarcely be mistaken. They are also predaceous in habit, 
but not nearly so ravenous as the " robber-flies," besides being 
much less abundant. 

A very interesting family is that of the " bee-flies," or Bomby- 
liidcB, which derive their common name from the fact that they 
are more or less covered with dense, diverging, whitish or yellow 
hair, giving them a close resemblance to certain bees. Many of 
the species occur in open places, hovering over bare spots, 
especially in spring, and they may be found at other seasons 
flitting from flower to flower, often poised in mid-air between or 
over them. There are two rather distinct series, one of them 
with robust species resembling a bumble-bee, and with a very 
long tongue ; the other much more slender, the species re- 
sembling flower-flies, with a much shorter proboscis and much 
less contrasting colors. The former are typified in the genus 
Bo7nbylms : the latter belong to Antlvax and allied genera. 
Their food is honey obtained from flowers, and the adults are at 
least innoxious. Among the species that occur early in the year, 
some are of direct benefit in the orchard, where they aid in pol- 
lenizing fruit flowers. The hairs composing the vestiture are 
fiirnished with little spurs or processes, or are twisted, so that 
pollen grains adhere readily. They are especially useful in 
cross-pollenation from their habit of flying considerable distances. 
The lar\'oe, on the other hand, are parasites, and distinctly bene- 
ficial in many instances. They prey upon the larvae of Lepidop- 
tera, including many of the cut-worms, and also infest the egg- 
pods of grasshoppers, forming one of the effective checks of the 
migrating or ' ' Rocky Mountain locusts' ' in this country. They 
are less beneficial when parasitic upon bees and other Hyme- 
noptera, but altogether the family may be said to contain chiefly 
useful species. 

Sometimes we find in houses, under carpets, a slender little 
larva nearly white in color, with a darker, rather indistinct, head, 
but without obvious legs. It is usually looked upon with sus- 
picion because of the locality in which it is found, but as a matter 



AA" ECONOMIC ENTOMOLOGY. 
Fig. 394. 




Bee-flies.— Fig. 394, Anthrax hypomelas : a, larva; b, the fly pupa projecting from a 
cut-worm pupa ; c, pupa ; adult. Fig. 395> lar^-a, with details, of Systcechus oreas, 
parasitic in grasshopper egg-pods. Fig. 396, pupa and adult of Syst(£chus oreas. 



THE INSECT WORLD. 



347 



of fact it is predaceous in habit, and feeds upon the species 
really infesting carpets and similar material. Thus, ' ' moths, ' ' 
the larvae of the ' ' carpet-beetle, " " fish-moths, ' ' and numerous 
other insects likely to 
occur in such situa- 
tions are destroyed by 
it. From this larva 
there comes in due 
time a small blue fly, 
a member of the family 
Scenopinidce ^ slender 
and somewhat flattened 
in appearance, with yel- 
low or reddish legs, and 
this may be sometimes 

seen upon the win- Scenophms fcnestralis. 

dows. These larvse 

have been often brought to me, and the little flies raised from 
them have always been Scenopinus fenestralis, from which Pro- 
fessor Comstock gives the group the name "window-flies." 

The remainder of the Diptera have the antennse short, rarely 
more than three-jointed, and usually with a bristle or style, called 
an "arista," which may or may not be feathered or plumose, 
from the second or third joint. The first of the families to which 
it is necessary to refer here is the Syrphidcs, containing a large 
number of species, most of them prettily colored, yellow, black, 
or bronze, patterned and marked in many different ways. They 
frequent flowers, hovering and often remaining suspended over 
them in mid-air for some time, then suddenly darting away and 
again returning. Their habits and appearance frequently give 
them a resemblance to bees and wasps, and in some species this 
is carried so far that they are easily mistaken for members of the 
order Hyme^ioptera by those not familiar with them. As a rule, 
^ the head is quite large, the body barrel-shaped, and the abdomen 
a little flattened, varying from very slender to broadly oval in 
shape. This abdomen is yellow and black, or bronze banded, 
sometimes entirely bronzed, more rarely blue or green, but 
nearly always brightly colored in some way. Some of the flies 
have the body distinctly covered with hair, though generally this 




348 



A AT ECONOMIC ENTOMOLOGY. 



Fig. 399. 



vestiture is confined to the thorax or trunk, and such species are 
sometimes of use in pollenizing flowers. I have found several 
species about fruit-blossoms in spring, moving from flower to 
flower, and, adhering to the vestiture, I have found pollen grains 
in considerable number ; so the insects are probablv of some 
importance in this direction. We have one very large species, 
Eristalis tenax, appearing late in fall, often in houses, and so 
closely resembling a honey-bee as to be generally mistaken for 
one ; for which reason it has been called the " drone-fly." It is 
frequent in greenhouses about the time 
that chrysanthemums are in bloom, and 
gardeners have assured me that pollen- 
izing this flower is done by it entirely ; 
hence they call it ' ' chrysanthemum 
fly." It is not at ail unlikely that this 
is the case ; indeed, it is even proba- 
ble, though sufliciently direct obser\^a- 
tions have not as yet been made in the 
matter. In this connection it is inter- 
esting to find that the body vestiture 
of the Syrphids is often composed of 
spurred and branched hair, similar to 
that found in bees, and in the ''drone- 
fly" this character is especialty marked. 

As widely divergent as the flies 
themselves are the larvae and their 
feeding habits. In fact, there is no sort 
of agreement ; and while some are pre- 
daceous, feeding upon plant-Uce or 
other insects, many feed in living or 
decaying vegetable substances, or in 
the foulest excrementitious material. 
Those forms that most concern the agri- 
culturist are the feeders on plant-lice, 
and these may be found at almost any 
time during the summer in almost e\'ery 
aphid colony, busily engaged in lessening its numbers. The 
larvse are easily overlooked, as they are usually green or yel- 
lowish in color, like the insects amonq- which thev feed. They 




1 

^^^^ 



Body vestiture of Eristalis 
tenax : a, entire hair; b, c, d, 
parts of same ; all greatly en- 
larged. 



Fig. 398. 




Bee-flies and flower-flies. — a, Bombylius sp. ; b, Bombylius sp. ; c, Anthrax sp. ; d, 
Eristalis transversus ; e, Eristalis tenax ;f, Eristalis saxorum ; g, Syritta pipiens. Some- 
what enlarged. From a photograph. 



THE INSECT WORLD. 



349 



are wrinkled and hairy when examined with a magnifying glass, 
soft in texture, thickened behind, and tapering almost to a point 
at the head, which is marked only by a pair of hooks and a 
little circular opening representing the mouth. They have no 
legs, and move by extending the body forward as far as pos- 
sible, then clinging with the anterior segments to the leaf or 
twig, and drawing the balance to meet the head. Awkwardly 
as they move, however, their progress is yet sufficiently rapid 
for their purpose. When once a larva has established itself in 
a colony of plant-lice, it never stirs until all in its immediate 
vicinity are destroyed ; it then moves only far enough to bring 
into reach additional prey, and so continues until no more re- 
main. The female lays her eggs close to, or actually among, 
an aphid colony, so that the larva finds food ready at hand 
as soon as it is hatched. It grasps a plant-louse with the 
mouth parts, lifts it from the surface, and sucks 
its juices, leaving the creature to struggle for 
a time, helplessly kicking its legs in mid-air. 
When the juices are exhausted the empty shell 
is dropped and another specimen is taken. 
When full-grown, the larva draws itself up 
into a humped mass ; the outer skin hardens, Syiphus larva de- 
darkens in color, and forms an apparently solid yo^rmg a piant- 

111-11 

covermg or coarctate pupa, beneath which the 

true or soft pupa of the fly is formed. Several broods of these 
predaceous flies occur in the course of the season, and they are 
among the most important checks that nature has provided 
against plant-lice increase. 

Others of the species are not quite so useful, and occasionally 
we have a form that is almost parasitic, living in nests of bum- 
ble-bees or other Hymenopterous insects and feeding upon 
their larvae. In such cases we often find that the flies greatly 
resemble in appearance the hosts among which they live. 
Among the feeders in vegetable matter we have a great variety 
of form, but they are usually more or less maggot-like and 
without legs. As they are not of particular economic interest, 
no more attention need be paid them here. The larva of the 
"drone-" or "chrysanthemum-fly," Eristalis tefiax, lives in 
masses of soft, decaying, or excrementitious matter. It is fre- 




35 o ECONOMIC ENTOMOLOGY. 

quently found in privies or cesspools, sometimes appearing so 
suddenly and in such numbers that a suspicion is engendered 
that the specimens have been passed by the individuals using the 
out-house. In fact, I have on more than one occasion received 
the larvae with the positive statement that this had actually 
occurred. They are curious creatures, maggot-like in general 
shape, with a long, extensile, tail-like appendage at the anal ex- 
tremity. It is hollow or tube-Hke, and at the end is a spiracle, 
the use of this telescopic tail being simply to keep the opening 
above the surface of the filthy mass in which the insect lives, and 
thus to secure a supply of pure air. The 
Fig. 401. larvae are called from this peculiarity " rat- 

tailed." The reason why the flies are 
^^^^^^^^^^V sometimes so abundant in greenhouses is 
'^^i^^^^^^^ that somewhere in their vicinity, among 
Rat-tailed larva of ^rzj^afe. semi Hquid mauurc, the best breeding- 
places can usually be found. Taken as a 
whole, this family Syrphidcs contains no really noxious insects, 
and many that are decidedly beneficial. It should be noted, 
however, that the larvae of some species feed upon pollen, and 
that others live in growing vegetable tissue ; hence it is not 
impossible that in the future this general statement may have to 



Fig. 402. 




Mesograpta poHta. — Larva, pupa, and adult; all enlarged. 



be modified. One of the most common Eastern species, Meso- 
grapta polita^ has been found feeding in great numbers in the 
larval stage upon corn pollen, but without causing any real injury. 

Passing over several small families interesting enough in them- 
selves, but not of importance to the agriculturist, we reach the 



THE INSECT WORLD. 



little family ConopidcB, which is not at all injurious, but rather 
the contrary. Professor Comstock calls them "thick-head flies," 
and the term is not bad, because the head is usually very promi- 
nent and as wide or wider than the body. The thorax is unusu- 
ally short, and bears a long abdomen having the 
basal joints very slender and the terminal joints Fig- 403- 
enlarged, bulb-like, much resembling in appear- 
ance that of certain wasps. The flies are moder- 
ate in size, with the wings more or less brown or 
clouded, and they may often be found on flowers 
after midsummer, in company with the Hymen- 
optera, which they resemble. The larvae are 
parasites, chiefly, it is said, upon bumble-bees and wasps, in 
which case they are not beneficial ; but also on grasshoppers, in 
which respect they deserve our most distinguished consideration. 

Distinctly injurious insects we find in the family CEstridce, or 
"bot-flies." These are usually of good size, sometimes even 
very large, and peculiar by having the mouth parts almost 
entirely aborted. Some of the species are very hairy, yellowish 
in color, and with rather a pointed abdomen ; while others are 
very plump, robust flies, blue or blue-black in color, often with 
a whitish bloom like that of a plum, formidable in appearance, 
though in fact entirely inoffensive in this stage. In the larval 
condition they are known as "bots," and live beneath the skin, 
in the intestines, or in the mucus-lined head passages of the 
animals infested by them. Thus, the "horse-bot," Gastrophilus 
equi, passes its Hfe in the stomach, attached to the inner coat, and 
there remains until full grown, when it releases its hold and is 
passed in the natural way through the anus. It then crawls into 
some convenient place just below the surface of the ground, or 
even among rubbish on top of it, and changes to a pupa. The 
adult lays its eggs on the hair, chiefly of the forelegs, at points 
easily reached by the tongue of the animal in licking itself. The 
eggs are thus removed, carried into the mouth on the tongue, 
and so into the stomach, where the larvae hatch almost immedi- 
ately and at once attach themselves. It is readily seen that this 
habit gives us a certain possibility of controlling the insects, 
because if the horses can be prevented from licking off the eggs, 
they never can reach the proper location for their growth. 




352 



AA^ ECONOMIC ENTOMOLOGY. 



Checking the animals up when in use accomplishes this, and a 
spiked muzzle, so arranged as not to interfere with feeding, will 
answer in the stable. Frequent brushing to remove the eggs is 
useful in bot-infested regions, and lessens the number that can 
reach the alimentary canal. 

Numerous other species occur just under the skin of the 
animals infested, and one of the best known of these is the " ox 
warble," Hypoderma lineata. Here also the eggs are laid on 
the hair and are licked off in the same way ; but the larvae, instead 
of allowing themselves to be carried into the stomach, pierce the 
oesophagus or other portion of the alimentary canal, and work 
their way through the muscular tissue to a point just below the 
skin. There they fix and increase in size, causing the swelling 
and suppuration so familiar to farmers in some localities. Of 
course the means just mentioned for preventing the entrance of 
stomach bots are also applicable in this case to avoid infestation. 
Where bots are already established on an animal, the best method 
is to incise the skin and press out the larva beneath it, or use a 
mercurial ointment, which, penetrating into the wound, will kill 
the larva, so that it can be readily pressed out later, or will sup- 
purate out easily. Some species of bot-flies undoubtedly lay 
their eggs on the skin of the animals at the points where the 
larvae actually hatch, and the latter work their way through just 
there and form the swelling. Sometimes special organs are 
attacked, as in the chipmunks and squirrels, where the testes of 
the males are selected and the creatures are actually emasculated. 
The fly has, therefore, been called the ' ' emasculating bot, ' ' Cuter- 
eh^a eviasadator. In rabbits a species is found close to the 
anal opening, and in fact most animals are more or less subject 
to bot attack. Even man is not exempt, and several cases have 
come under my observation where flies had laid their eggs on the 
skin and the bots had developed considerably before the charac- 
ter of the trouble was understood. In southern countries this is 
much more likely to occur than in the north, possibly because a 
much greater part of the body is there habitually exposed. 

Sheep suffer from a species known as CEstrus ovis, which lays 
its eggs on or in the nostrils. The larvae make their way through 
the nasal passages in the mucus beneath the skin, and even into 
the horns. They are often very troublesome, and cause one 



THE IX SECT WORLD. 



353 



form of the disease known as " staggers," which is sometimes 
extremely destructive to herds. 

From this description of the Hfe histories, so briefly given, it 
appears that our efforts to avoid injury must follow in the direc- 
tion of prevention. As against the species that must first be 
taken into the mouth, the mechanical ways of preventing a 
horse or an ox from licking any part of the body will prove suffi- 
cient ; or frequent brush- 



ing will at least moderate 
the injury. 

In the case of the 
sheep-bot the matter is 
more difficult, because the 
flies are very persistent, 
and encircle the animals 
until they get an oppor- 
tunity to dart to the nos- 
tril and deposit upon it 
^§'& j^^t ready to 
hatch, or already hatched, 
so that either immedi- 
ately or in a very^ short 
time the maggot makes 
its way up along the mucous 
allow it to extend. 



Fig. 409. 




The sheep-bot, CEstrus ovis. — i, 2, nies ; 3, pupa 
4, 5, full-grown larva ; 6, young larva. 



membrane as far as the passages 
All sorts of devices have been adopted to 
prevent this, but none are entirely satisfactory. Tar has been 
used as a repellent, smeared on the nose, and with more or less 
success. It is probable that fish oil and oil of tar, or carbolic 
acid, would answer the same purpose. Powdered tobacco, used 
to induce the sheep to sneeze and thus dislodge any maggots 
that had already made their way in, has also been more or less 
satisfactory-. In the case of recently infested animals, a brush 
dipped in turpentine and carefully used in the nostrils, so as to 
reach attached larvae and kill them, is sometimes found useful. 

The family MuscidcB is the largest in number of genera and 
species in the order as well as the most difficult to classify. The 
common "house-fly," the ''blue-bottle," and the "flesh-fly" 
are examples, and may be considered as typical forms, which 
most of the species resemble ; not necessarily in color or mark- 

23 



354 



AJ^ ECONOMIC ENTOMOLOGY. 



ings, but in general type of structure. It is almost impossible 
for any but the special student to distinguish between even the 
sub-families, and yet these differ greatly in habit, some being 
decidedly injurious and others as decidedly beneficial in the 
larval stages. One of the peculiarities of all the members is very 
short antennae, in which the terminal joint is long and stout and 
furnished with a bristle or arista attached near the base. The 
modifications of this bristle aid in distinguishing the groups. 

The Tachina flies, for instance, have the bristle entirely bare, 
though otherwise many of them resemble the common ' ' flesh- 
fly' ' or the ' ' blue-bottle. ' ' They are generally rather large, 
robust in appearance, always bristly, and sometimes formidable 
looking from the array of sharp spiny points projecting in every 
direction. They are parasitic in habit, largely upon caterpillars, 
and among them perhaps preferably upon cut-worms. Fre- 
quently, where the latter are numerous, a large percentage will 
be noticed with one or several little w^hite eggs attached on the 
anterior segments, just back of the head, in such a position that the 
larvae cannot possibly reach or destroy them. These eggs hatch 
in a very short time into little maggot-like creatures that at once 
bore through the skin of the caterpillar and live within its body, 
feeding upon the fatty masses and muscular tissue not absolutely 
necessary to life. When the maggots are full-grown and the 
welfare of the caterpillar is no longer a matter of importance to 
them, they feed on regardless of consequences, and the creature 
dies. The maggots, sometimes without even attempting to get 
out of their host, then change to barrel-shaped pupae. This is 
accomplished by a contraction of the larval skin, which hardens 
and becomes brown in color, releasing its hold at the same time 
on the forming (true) pupa beneath. Occasionally the maggots 
leave their host and make their way a little below ground to 
pupate. Some of our large caterpillars attain their full growth 
with as many as thirty or even more of these maggots feeding 
upon their vitals. Some of the flies are very handsome and 
strikingly colored, as, for instance, the Tachina vivida, in which 
the abdomen is bright red, set with black spines, — a very remark- 
able looking species. Others are black, the abdomen banded 
with yellow ; but as a rule they are of a modest gray color, the 
thorax rather obscurely streaked with blackish brown or gray. 



Fig. 413. Fig. 410. 




Fig. 415. 




Muscid flies.— Fig. 410, Exorista flavicauda, yellow-tailed Tachinid. Fig. 411, ISe- 
morea leucanics, Tachinid on cut-worms : larva, pupa, adult, and the white eggs on 
the anterior segments of the caterpillar. Fig. 412, Lydella doryphorcs , Tachinid on 
potato-beetle. Fig. 413, common flesh-fly, Sarcophaga carnaria. Fig. 414, the blow- 
fly, Calliphora vomitoria. Fig. 415, screw- worm, Lucilia tnacellaria : a, b, c, larva and 
details; rf, pupa ; ^, adult ; /, head from side. All are enlarged, and Fig. 413 very 
much so. 

355 



356 



AA^ ECO XO MIC ENTOMOLOGY, 



These flies are among the most eflective of nature's checks to 
caterpillars, especially cut-worms. 

The ' ' flesh-flies' ' greatly resemble the Tachina flies in ap- 
pearance, but the arista or bristle of the antennae is feathered 
towards the base and is bare only at the tip. Some of these 
species also are parasitic. Others have larv^ that live in excre 
mentitious material, in fruits, in meats, or in decaying animal or 
vegetable matter generally. Such species usuallv produce their 
young alive, or at least as eggs just ready to hatch, and the 
majority are scavengers. None of the members of this family, so 
far as I am aware, are injurious, and they are ahvays beneflcial to 
the extent, at least, of assisting in the remo\'al of oflensive matter, 
animal or vegetable, 

The typical Muscids difter from the other species in this series 
by lacking the spines of the thorax and abdomen, or ha^'ing them 
confined, in a very reduced state, to the tip of the abdomen only. 
The arista orantennal bristle is feathered to the tip. The house- 
fly is one of the best known of all insects the world o\'er, and 
there seems to be no region where it does not occur and is not 
more or less annoying. It winters in our houses or out-buildings, 
hiding in some sheltered spot in cellar or attic, or remaining 
more or less active in our carefuUy warmed rooms. During the 
early days of spring a few specimens make their appearance here 
and there, sole survivors of the swarms of the preceding year. 
These are mostly females ready to reproduce, and they lay their 
eggs in any convenient pile of horse manure ; or, if that is not 
available, in any decaying animal or \-egetable matter. The 
maggots hatch in a day or two, in a week or ten days are full- 
grown, change to pup^, and in a very few days more a new 
brood of flies is matured, already sufflcient in numbers to become 
more or less annoying. This process is repeated time and again 
during the season, and the insects increase in numbers until alter 
midsummer, when they seem to lose activity to some extent, 
although breeding until cold weather actually sets in. House- 
flies are not injurious in any true sense of the word, although they 
are distinctly annoying and may become dangerous by trans- 
ferring disease germs from one point to another ; as when, after 
alighting and feeding upon the sputum of a consumpti^'e, they 
tickle the nose of a healthy sleeper a few minutes thereafter. So 



THE INSECT WORLD. 



blood poisoning may be set up by a fly which has been feeding 
upon a putrefying carcass and then feeds upon an abraded sur- 
face or a cut or bruise on man. This, however, is not a common 
occurrence, and perhaps as a scavenger the insect is about as 
useful as it is annoying. A single female produces on an average 
about one hundred and fifty eggs, and this, with the short period 
required to bring them to maturity, accounts for the enormous 
increase of the insects. After a fly has attained this stage it 
never grows more, and a small fly never makes a large fly, any 
more than the progeny of a large fly is ever a small fly. 

The "blow-fly," Calliphora vornitoria, is the largest of the 
common species abundant enough to attract attention, and this 
has the body of a deep blue, almost black, color, the abdomen a 
little lighter and somewhat more shining. It is an obtrusive 
creature and noisy withal, especially when flying about on the 
windows or bumping against the ceilings of a room, making its 
presence obnoxious in more ways than one. Its eggs are laid on 
all sorts of animal and vegetable matter in an incipient stage of 
decay. Meat exposed in summer is almost certain to show, in a 
very short time, little piles of elongate white eggs scattered over 
the surface here and there. Fish are especially subject to attack, 
and I have myself had the experience that a little string of fish 
laid in the shade of a bush on the bank was covered with such 
eggs before I was ready to go home. Of course they could be 
readily washed off, and it is not usual for this insect to retain the 
eggs until they hatch within the abdomen, yet I have found 
specimens that have done so. This species also requires but a 
very short period for its development, and its rate of increase is 
so great that it has given rise to the saying that a pair of flies 
will devour an ox more rapidly than will a lion. A carcass left in 
the fields during midsummer becomes, in fact, in a few days a 
mass of maggots, which soon leave nothing but hide and bones. 
A somewhat smaller species than this blow-fly, of a very much 
- brighter green or bluish color, with four longitudinal lines on the 
thorax, is the "screw-worm" fly, Lucilia 7nacellaria. This is a 
common species throughout a large portion of our country, and 
ordinarily feeds upon dead or decaying animal matter. Under 
some circumstances, however, it attacks living animals, and in 
the Southern and Southwestern States occasionally becomes a 



358 



AN ECONOMIC ENTOMOLOGY. 



terrible pest. On such occasions it lays its eggs on man or 
animals wherever there is the slightest trace of a wound, bruise, 
or offensive discharge of any kind. The larvae bore directly into 
the living flesh, causing intense pain as well as suppurating sores. 
Living larvae are produced as well as eggs almost ready to hatch, 
and into any opening from which there is a discharge of any 
kind eggs may be deposited. Sleeping humans with an offen- 
sive breath, or with a fetid discharge from the nostrils or mouth, 
have had eggs laid at these points, and larvae have made their way 
into the head, in some cases causing the death of the individual. 
Eggs have also been laid in the ears of uncleanly people, and the 
channels and passages of this organ have been penetrated into the 
head and destroyed. Animals are troubled in the same way, and 
where the insects are abundant, their attacks often become fatal. 
The only remedy is cleanliness. Wounds, even of the most 
trifling nature, on cattle should be smeared with an antiseptic 
ointment. As far as possible, all materials in which the flies can 
breed should be destroyed ; no accumulation of animal refuse 
should be allowed under any circumstances, and by strictest at- 
tention to surroundings, the breeding of the insects should be 
prevented. Attacking Hve animals is not a usual habit, although 
very readily assumed when the insects become abundant. 

Another insect, a trifle larger than the house-fly and much 
like it in appearance, though a little more robust, is the ordinary 
stable-fly, Stomoxys calcitrajis. This has the mouth parts formed 
for piercing, and annoys animals by alighting upon and sucking 
the blood of parts that cannot be reached by them with head or 
tail. Sometimes these insects also attack man, especially late in 
the season or in heavy weather. They have an especial fondness 
for human shanks, and readily bite through stockings ; sometimes 
through trousers as well. This bite is painful, though it rarely 
leaves a swelling or perceptible inflammation. The larvae develop 
in horse and cow manure, and their increase in stables can, there- 
fore, be checked to some extent by promptly removing and 
placing this in pits, or mixing with plaster or other material that 
will absorb the moisture and fix the ammonia. 

A close ally of the stable-fly is the so-called horn-fly," 
Hcsmatobia serrata, a recent introduction into the United States, 
which has spread over the country with almost phenomenal 



THE INSECT WORLD. 



359 



rapidity. This insect derives its common name from the fact 
that it seems to prefer clustering in great numbers at the base of 



Fig. 416. 




Horn-fly, Hcematobia serrata.—a, egg; b, fly; c and rf, head and mouth parts; all 

enlarged. 



Fig. 417. 



the horns of cattle, although it is really just as abundant on the 
flanks, upon the udder, and in other places where it cannot be 
readily reached by the animals. The fly seems to confine its at- 
tacks to horned cattle, although it has been seen on mules in the 
State of New Jersey. Like the stable-fly, it 
is a blood-sucker, and both species are often 
found on animals at the same time, keeping 
them in that state of constant irritation 
which prevents their proper feeding and 
digesting, and keeps them poor and in no 
condition to produce a free flow of milk. 
Not only in the fields or pastures are the 
cattle annoyed by these insects, but in the 
stable as well, so that the animals get no 
rest night or day. Eggs are laid in fresh 
cow-dung, and before this has an oppor- 
tunity to dry under ordinary conditions, the 
larvae are full-grown and ready to pupate. It is the immense 
number of these insects that makes them dreadful, and when the 




Egg of horn-fly. — i, 
unhatched, from side; 

2, hatched, from front; 

3, same, from side, to 
show lid-like structure; 
all enlarged. 



36c 



A^' EC 0X0 MIC EXTOMOLOGY. 



hornb.e tales were told of the cestru::: : c^u~-rc 
of cattle. As a matter of lac:, exc-e::: f : : irriii::; ::, 
no injur}". Aluch can be dir.e Ij ^.ire'.'er.: :r.c :::;r-^?e 
insect by destroyir.g the hreechr.^--:: laces. I" the stable. :: 
and their surroundings should be ke^: ab5:h.:.:elv ;lr 
whitewash should be hberally applied. The :v.i::urr sh 
mixed at once with either kainit cr la::i iliL5:er, whi:h 

the n:'::s:-:re a::d :::al:e5 :h 



Fig. ^i8 




srmctural detai 



cru< 



r}' are 



to give a decided odor is ail that is r.eirfsiry, a::;' cr.t ap^li 
will usually suffice to protect an a::in::.- fir f-.-e ir six ili^ys. 

Another series of decidedly troublesome hies we hnd 
Anthom3'iids, whose lan^s are ffecxer.rly reor-ir.festire' m = 
The adults closely resemble the cirn:. ir. h i use-hies, iiu: ar 
ally somewhat smaller in size and sii^ha:er in fuiid. Th 
found in fields on the ground, cn '.-eii-rtah i if aii kir. ds. a: 
also commonl}- enough incur houses 1:1 hue uhud 1 ivs, -vhere they 
are usually mistaken for the true house-hy, Reci euiiiir. cf the 
species of these flies is a matter of n a great in: C' ir:i.r. le a radi- 
cally ; but it may be assumed, where hies resen-fciia^- hae irdiaarA' 
household pest in all save size arr uiiiiea ia aay auaider adiut 
crops subject to infestation by ra ::-n:ai-gi:s, :i:a: -.ve have —em- 
bers of this Anthomjnid series to deal with. They are ohen ver}- 



THE IX SECT WORLD. 




injurious to cabbage and cauliflower, as well as to onions, rad- 
ishes, turnips, beets, and other root crops, while other species 
attack planted seeds 
like those of melons 
and even corn. Oc- 
casionally, instead ol 
attacking roots, the 
maggots are found 
boring in thick or 
fleshy leaves, and 
then they make 
mines or galleries be- 
tween the upper and 
lower surfaces, often 
doing much injury. 
Sometimes their hab- 
its are more like 
those of the house- 
fly, and the lan-ee are 
scavengers, while a 

few have been recorded as parasites on other insects. The 
group, therefore, is one with diverse habits, but usually to be 
looked upon with considerable suspicion. Perhaps the best 
known of the root-maggots is the lar\-a of Phorbia brassiccB. in- 
festing cabbage, cauliflower, and other plants of the same natural 
family. Eggs are laid on the ground soon after the plants are 
set out in the fields. The larA'se make their way into them as 
soon as they are hatched, gnawing or rather scraping the tissue, 
so as to enable them to absorb the plant juices, for they have no 
jaws for mastication. Decay sets in where the insects work, and 
this favors their feeding, so in a few days they destroy the tissue 
of the plant and stem a little below the surlace so completely that 
it dies. Later crops are not so much harmed, as a rule, and if 
plants can be preserA'ed until they reach a good size, they fre- 
quently sustain considerable maggot attack without serious in- 
jur}-. As to the best remedies against this particular insect we 
are yet somewhat uncertain. Putting a pad or disk of tarred 
paper on the stems of the plants when they are set out has been 
found successful in preventing the adult from laying eggs, or the 



Cabbage-maggot, Phorbia brassiccs. — a, lar\-a ; b, pupa 
c, adult : d, its head ; e, antenna. 



362 



AA^ ECONOMIC ENTOMOLOGY. 



larvae from getting at the desired point, since they seem to be 
unable to live exposed to sunlight. Ground tobacco, kerosene 
and sand, plaster, soot, ashes, and other materials placed at the 
base of the plants act like the tarred paper as a mechanical pro- 
tection, and must be appHed before the eggs are laid, else they 
will prove ineffective. Bisulphide of carbon injected below the 
root system has been used with a considerable degree of success, 
the fumes filtering through the soil and kilhng the insects at 
work on the plant without injuring the plant itself. An injector 
devised for the especial purpose has been made by Mr. J. J. 
McGowen, of Ithaca, New York, and perhaps the application of 
this substance is the most certain and satisfactory remedy that 
has been proposed. It should be used when the soil is moist, 
but not water-soaked. There are two or three broods in the 
course of the year, according to latitude. The winter is passed 
either as a pupa below the surface or as an adult in barns, 
houses, etc., and the species is tided over between cultivated 
crops by the cruciferous weeds. Hence clean culture and the 
prompt removal of all crop remnants are urgently indicated. 
Carbolic acid and kerosene, emulsified with soap according to the 
formulas elsewhere given, have proved effective as killing agents 
when the maggots have begun feeding. Pour about half a pint 
around the base of the infested plant, diluting the carbolic acid 
emulsion thirty times and the kerosene emulsion twelve times. 

Radishes frequently suffer from the attacks of the same 
maggots, and they are more difficult to deal with here, because 
they puncture the fleshy root and make channels through it in 
every direction, safely beyond the reach of any insecticide appli- 
cation. It rarely pays to put expensive substances on radishes, 
because the margin of profit is too small ; but considerable 
benefit may be derived from proper methods of fertilizing, and 
the mixture that seems to offer the best chance for success is 

Nitrate of soda 700 pounds. 

Ground rock 1000 pounds. 

Muriate of potash 300 pounds. 

Apply soon after the plants are up, or when the leaves are about 
an inch long, at the rate of five hundred pounds per acre, and 
before or during a rain. The application made at this time seems 



THE INSECT WORLD. 



363 



to reach the maggots just when they are hatching, and becomes 
effective for that reason. Apphed later, when the insects have 
already made their way into the radishes, it would be useless. 
Here the farmer must necessarily make a few observations of his 
own to determine the proper time for applying the fertilizer 
remedy, and this is not difficult. The flies lay the eggs in little 
masses on the surface of the ground near to the infested plants. 
They are white, slender, and cyHndrical, nearly one-sixteenth of 
an inch in length, and quite visible on close examination. When 
these eggs are found generally distributed over the fields the 
time to make the insecticide apphcation has arrived, because they 
hatch only a few days after they are laid, and the young larvae 
must be reached then or not at all. The carbolic acid emulsion 
diluted thirty-five times may also be applied with good prospects 
of success in killing the maggots, or the ground tobacco may be 
used over the rows just as soon as the plants are up. 

The onion-maggot, Phoi^bia ceparum^ is, perhaps, next in im- 
portance, and its habits are essentially the same as those given 
for the cabbage-maggot, — that is, the eggs are laid by the fly 
quite early in spring, 
next the onion stems or 
leaves at the surface of 
the ground, and prefer- 
ably in young onion 
beds. In the latitude of 
New Jersey this occurs 
in May, but the date va- 
ries somewhat accord- 
ing to the season and to 
the time at which these 
plants are started. The 
larvae work their way 
into the bulb at once 
and begin their scraping 
and gnawing, leading to 
the rapid decay and death of the plant. Matters are even more 
serious here than in the cabbage, because where a bulb has been 
started in decay, it usually continues, even if the maggots are de- 
stroyed, and in the case of sculHons, they become unmarketable. 



Fig. 420. 




The onion-maggot. — Larva, pupa, adult, and section 
of an infested onion. 



3^4 



AA^ ECONOMIC ENTOMOLOGY. 



The maggots attain their growth about the end of May or early 
in June, and before the middle of that month a second brood of 
flies may be found in the fields. This second brood is often 
much the most injurious, and quite frequently it attacks seedling 
onions, ruining entire beds. The older plants, if they have 
reached this date unharmed, are usually safe for the year. Exactly 
how many broods there are has not been accurately ascertained, 
and probably the number varies somewhat according to latitude. 
We do know that the insects pass the winter partly in the pupa 
stage in the ground, and partly as adults in barns, farm-houses, 
and other sheltered localities. Many measures to prevent injury 
have been proposed, none with any marked success, except those 
here mentioned. The most promising is sand soaked in kerosene, 
one cupful to a pail of dry sand, and placed at the base of the 
onion plants along the rows. This prevents egg-laying by the 
fly, kills any young larvae that may attempt to work through it, 
and seems to have been quite satisfactory where tested ; but it is 
obviously not a suitable measure for application on a large scale. 
In New Jersey tons of onion seed and sets are raised annually, 
and the following practice has been found uniformly successful. 
Keep a close watch for the first signs of maggots ; carefully Hft 
out and destroy all infested plants that have wilted down so far 
that they cannot survive, and so kill the more advanced maggots. 
Turn away the earth from the rows with a hand-plough so as to 
expose the root system in part, then apply broadcast about six 
hundred pounds of kainit and two hundred pounds of nitrate of 
soda per acre ; turn back the earth to the plants, and this will put 
a period to the injury. The application is best made just before 
or during a rain, or immediately after a shower that has wet 
down pretty thoroughly. The object is to get the salty fertilizers 
dissolved rapidly and brought into direct contact with the roots 
of the plant, and, of course, with the insects as well. This 
method has proved entirely satisfactory in New Jersey, and on 
light lands it will probably act equally well in other localities ; 
but it has never been tested on heavy land, and the action may 
not be entirely the same. The application of the fertilizer has the 
advantage of imparting additional vigor to the plant, and stimu- 
lates it to overcome such injury as may have been already caused. 
It is a good plan always and under any circumstances to care- 



THE IXSECT WORLD. 



365 



fully take out and destroy plants that have wilted down beyond 
recovery, because in this way the maggots are destroyed or pre- 
vented from coming to maturity. 

Other root-maggots may be treated on the lines just laid down, 
and nothing can be gained by multiplying instances. Too little 
is known of most of the leaf-miners to give any general directions 
concerning the methods which may be used to check them ; but 
one remedy, or rather preventive measure, is always useful. A 
crop of infested leaves should always be disposed of as soon as 
possible. For instance, if beet leaves are attacked at the time 
the roots are harvested, they should be at once destroyed, and 
with them the insects yet in the plants. In this way much can 
be done to lessen their number for the ensuing season. Direct 
applications for leaf-miners are unsatisfactory, because of the 
difficulty of reaching them. 

The remainder of the Muscid flies differ from all the preceding 
in that they have no perceptible winglet or alulet just below the 
anterior wings. If the " blow- fly" or the ''house-fly" be exam- 
ined, it will be found that just behind the base of the large wings 
there is a little flap resembUng in appearance a minute wing. 
This is called the "winglet" or "alulet," and it is more or less 
obvious in all the Muscids of which we have heretofore spoken. 
It is absent in all the other groups, and serves to divide this 
large family into two fairly distinct series. 

We find it absent in a large series of flies belonging to the 
Trypetids and Ortalids, which are usually small in size, often 
metallic in color, and with the wings frequently banded or mot- 
tled. Some of the species have the habit of strutting up and 
down with the wings elevated and spread out, and this has given 
them the name "peacock flies." They are gracefully built in 
most instances, and are noticeable by keeping the wings in con- 
stant motion even when feeding or walking about on flowers, 
where they are most frequently found. They fly rather slowly, 
and, as a rule, are easily captured. The abdomen of the female 
frequently ends in an extensile, horny-tipped ovipositor, by 
means of which the eggs are laid in the plant tissue in which the 
larvae feed. Most of the members of the series feed in plant 
tissue of some kind, either in leaves, in stems, or in fruits, and a 
number of them are gall-makers. The most notable instance of 



366 



AA^ ECO XO MIC EXTOMOLOGY. 



the latter type in the Eastern United States is seen in the round 
swelHngs so frequently found on the stems of golden-rod. A 
number of species are locally injurious to fruits, but there seems 
to be no one injurious form generally distributed throughout this 
country. In the Northern and Eastern United States the so- 
called " apple" -maggot, Trypeta pomonella, is the only one 
causing trouble, the fly laying its eggs in the tissue of the apple by 



Fig. 421. 




Trypeta pomonella, parent of the apple-maggot. 



piercing the skin with its horny ovipositor. The little maggots 
channel the fruit in every direction, causing it to rot or become 
unsalable. When full-grown they pupate below the surface of 
the ground, or even among rubbish on the surface, or in crevices. 
Indeed, they are not at all particular, and transform wherever 
they can find an opportunity to do so, including the barrels, 
boxes, or bins in which infested apples have been kept. None of 
these fruit flies can be reached by insecticides, nor is there any 
fair chance of reaching the adults, and the only method that 
is effectual is the prompt removal and destruction of infested 



THE INSECT WORLD. 



367 



fruit. Windfalls should be picked up constantly and destroyed 
at once. Summer varieties, especially sweet types, are most in- 
fested, and these should be sent to market at once if the apples 
are marketable, or if they are not, they should be disposed of in 
some effective manner to prevent the maturing of the flies. They 
seem to be more common in the Northeastern States, extending 
southward only to Central New Jersey. South of this point they 
seem to be unknown, or so rare as not to be injurious. 

Probably every one has noticed in the fall, at cider making, or 
when grapes are pressed for wine, or, in fact, whenever there is 
an accumulation of fruit of any kind in which fermentation or 
decay has started in ever so slight a degree, that swarms of little, 
yellowish flies make their appearance, easily distinguished by 
the bright coral-red color of the eyes. No specimens may have 
been noticed previously ; but just as soon as the material at- 
tracting them makes its appearance, swarms are seen coming 
from no one knows where. They lay their eggs in the ferment- 
ing or decaying mass. 



and a few hours after- 
wards there will be an 
abundance of small, 
white, wriggling mag- 
gots. These become 
mature in three or four 
days, and after another 
day or two in the pupa 
state, they develop into 
adult "pomace flies," 
species of Drosophila. 
and a little troublesome, 



Fig. 422. 




A pomace fly and 




Drosophila species ; 



The insects are sometimes annoying 
but scarcely injurious, and it is only 
because they are so common and occur so suddenly in large 
numbers that they are mentioned here. Little attention is paid 
to the larvae either in wine or cider making, because they are 
thrown out in the process of fermentation, and do not in any way 
affect the quality of the resulting product. 

To this same family belong the " skippers" which are found in 
cheese and sometimes in other kinds of provisions. The term 
is derived from the habits of the larvae, which move about by a 
series of little jumps somewhat resembling those of the larvae 



368 



AN ECONOMIC ENTOMOLOGY. 



of the Cecidomyidcs. They produce a Httle black fly, Piophila 
casei, similar to the house-fly in appearance, but much smaller, 
and the only way to protect provisions is to keep them con- 
stantly covered. They sometimes become an intolerable nuisance 
in smoke-houses, attacking ham, bacon, and the like during the 



sary to get rid of them. In the first place, windows should be 
closely screened to prevent their entry from outside ; the walls 
should be whitewashed frequently, so as to keep all crevices 
filled up ; the floors should be kept clean, and should be as solid 
and smooth as possible, to prevent the development of maggots 
in crevices filled with greasy substances. The flies can be killed 
by fumigating with tobacco or pyrethrum, and this should be 
done by closing up the rooms tightly in the evening after work 
is done, or on a Sunday or other day w^hen work ceases, and a 
suflicient quantity of either tobacco or pyrethrum should be 
burnt on live coals to completely fill all parts of the rooms. They 
should be left tightly closed anywhere from eight to twenty-four 
hours, and at the end of this time the flies will have been de- 
stroyed, but the maggots will not, and it will be necessary to 
repeat this operation two or three times, at intervals of (at most) 
a week, to destroy the flies as fast as they hatch, and before 
they have an opportunity to lay their eggs. In some cases bi- 
sulphide of carbon may be used to fumigate ; but this must be 
done when there is no fire on the premises, and the house 
should be left closed twelve hours at least, and should then 



Piophila casei, parent of "skippers" in cheese, 
etc. 




Fig. 423. 



process of smoking, or be- 
fore they can be cased, and 
the value of the provision 
is frequently impaired by 
the development of these 
maggots. Where a house 
is once thoroughly in- 
fested, the flies are found 
in swarms everywhere, 
ready to attack the meats 
as soon as there is the 
least opportunity. Under 
such circumstances thor- 
ough measures are neces- 



THE INSECT WORLD. 



369 




A louse-fly, Olfersia species. 



be aired until no trace of odor remains before fires are again 
introduced. 

The last family in the Diptera to which we need call attention 
are the "louse-flies," or Hippoboscidcs, frequently separated as 
a sub-order under the term Pupipara, the latter being applied 
because of the curious method of reproduction. The flies are 
parasites, living largely upon birds, but sometimes upon animals, 
and the egg not only 

develops within the Fig. 424. 

body of the female, but 
the larva becomes nearly 
full-grown in the same 
position, and practically 
attains the pupa state 
before it is extruded. 
In these species the ab- 
domen is somew^hat flat- 
tened and oval in form, 
of a thick, leathery con- 
sistency, with a very 

large anal opening, and from the circumstances of the case only 
one larva at a time is produced, so that the flies produce young 
only at considerable intervals. The whole body is depressed or 
flattened, and birds of prey are most usually affected. It is rare 
to find a hawk, eagle, or owl upon which several specimens of 
these peculiar flies cannot be found. They 
move about rapidly, and their first impulse is 
always to seek shelter when driven from their 
original host. Thus, in handling hawks that 
have just been shot, the flies frequently dart 
upon the hunter and make their way under his 
clothing and to his body. 

A few species are wingless, and among them 
is the so-called "sheep-tick," Melophagus 
ovinus, which is usually looked upon as a 
louse, and resembles one in the prominent 
proboscis, the lack of wings, and the strongly developed legs, 
on which the claws are very prominent. This "sheep-tick" is 
the only troublesome species, and it can best be kept in check 

24 



Fig. 425. 




Sheep-tick, Melopha- 
gus ovinus. 



370 



AN' ECONOMIC ENTOMOLOGY. 



by frequent dipping, using a carbolated dip which readily de- 
stroys the insect. Thorough washing after shearing will usually 
clear the animals completely, and if the entire herd be once 
freed, it will remain so until infested animals are introduced. 
The parasites are able to move from one to the other only when 
the animals are herded close together. 

Yet more louse-like in appearance is the little whitish creature, 
Braula ccEca^ found upon the honey-bee as a parasite ; but it 



Fig. 426. 




Bee-louse, Braula cczca, and its larva ; much enlarged. 



seems to be rather rare, and, in our country at least, does not 
assume the dimensions of a serious pest. 



CHAPTER IX. 

THE HYMENOPTERA. 

Bees, Wasps, Ants, Saw-flies, etc. 

There is no order of greater interest than this, containing as 
it does the bees, wasps, and ants, the most useful as well as the 
most intelligent of the insects. By treating them last, the inten- 
tion is not to suggest that they are lowest, but rather that they 
are the culminating point in the development of the class. Here 
we find social organizations not unlike some of our own systems 
of government, but more complete and running much more 



THE INSECT WORLD. 



smoothly. We find division of labor carried to an extreme ; 
combination for special purposes ; skill and energy in the prepa- 
ration of homes ; and, finally, we discover the helpless young 
cared for by parents or nurses. It is only in the Hymenoptera 
among insects that we find true babies, — that is, young that must 
be fed and tended until they are ready to assume the adult form. 
Nowhere else do we find larvae fed on anything but simple, 
natural food ; but by many bees a mixture is prepared and fed ; 
not honey or pollen alone, but a combination of the two in defi- 
nite proportions is given, and these proportions vary with the 
sex of the larva. 

Members of the order Hymenoptera may always be distinguished 
by the presence of four transparent wings, the anterior always the 
larger, the secondaries frequently very small. They are not cov- 
ered with scales, but are often set with small hair, and the cells 
and veins are comparatively few in number ; - never netted as in the 
Neuroptera. The mouth parts are mandibulate, or formed for 
biting, but in many of the families there is also developed a large 
tongue-like structure which serves for lapping, none of the Hy- 
menoptera being strictly haustellate, or sucking insects. The 
metamorphosis is complete. 

Taken as a whole, the order contains beneficial insects ; but as 
there is no rule without exceptions, so we find here also one 
series the species of which are vegetable feeders. These are in- 
cluded in the families TejithredinidcB and UroceridcB, the "saw- 
flies" and "horn-tails." 

The term "saw-flies" is used to indicate a series of species 
peculiar by the structure of the ovipositor, which is made up of a 
number of parallel blades toothed at the edge, by means of which 
the insects are enabled to cut pockets or slits in leaves or other 
vegetable tissues to receive the eggs. They are further peculiar 
by having the abdomen sessile, or joined for its full width to the 
base of the thorax, and the wings are rather larger in proportion 
to the body than in other groups. The larv« are caterpillar-like 
in appearance, but they always have at least one more pair of 
prolegs than any caterpillar, — six pairs or more, of which one 
pair is anal, — which renders them easily distinguishable. They 
are often more or less slimy in appearance and to the touch, and 
perhaps a majority have the. habit of coiling the posterior por- 



372 



A TV ECONOAIIC ENTOMOLOGY. 



Fig. 428. 



tion of the body around the edge of the leaf or twig while feed- 
ing. This is quite a characteristic peculiarity, and there is rarely 
excuse for mistaking the larva of a saw-fly for that of a Lepidop- 
teron, even without counting the prolegs. Many of these larvae 
are injurious to cultivated plants, and some of them are known to 
farmers as "slugs" or "worms;" for instance, we have the 
" currant- worm," the "grape-slug," the "rose-slug," and the 
"pear-slug." When these larvae are full-grown they form thin, 
tough, parchment-like cocoons, in which they change to pupae, 
sometimes on the plant on which they feed, sometimes a little 
below the surface of the ground. 

Perhaps none of the members of this family are better known 
than the "currant-worm," or "slug," Nematus ribesii, which is 
an imported insect, and annually does great injury where its food 
plant is raised on a large scale. The flies, which are easily dis- 
tinguishable by a rather deep yellow body, may be seen sitting 
upon the foliage, or flying about heavily as 
soon as the leaves of the currants are toler- 
ably well developed in spring, and we may, 
even at that time, find on the under sides, 
arranged along the veins, series of little 
white eggs laid by them. The larvae soon 
make their appearance and feed ravenously, 
frequently stripping a bush completely in 
the course of a few days. I have seen rows 
of currants covering an acre or more almost 
entirely devoid of leaves and the fruit hang- 
ing to bare twigs. There are two or three 
broods in the course of a season, depending 
upon latitude, the latter rarely as abundant 
as the first and second, and practically not 
nearly so destructive. The larva is green, 
dotted with black, and nearly an inch in 
length. 

On pears we frequently note a very dark green slug, the larva 
of Eriocampa cerasi, which is more or less slimy to the touch. 
On young trees this sometimes does much injury by scraping 
the upper side of the foliage until it dries and withers, falling to 
the ground in midsummer. 




Pear-slug, larva of Erio 
campa cerasi. 



Fig. 427. 




Fig. 427, currant- worm. -a, a, male and female adult; b, larvae; c, pupa in {d) cocoon- 
e eggs. Fig. 431, Phyllcecusflaviventris.-a, female adult ; 5, c, male and female abdomen • 
a, spur of anterior tibia. 



373 



374 



A.V ECOXOMIC EXTOMOLOGY. 




On grapes there are often black-dotted slugs, the larvse of 
Blennocanipa pygmcsa, that do some injury ; and on roses almost 
ever}" grower has been annoyed by numer- 
ous green slugs, the lar^^ae of Monostegia 
roscB, which make their appearance early in 
the season. 

Raspberries are sometimes severely in- 
jured by Httle spiny slugs, the larvse of 
Mojwphadnus rubi, that appear in June or 
early July, first eating round holes in the 
leaves, but e\'entually, when they become 
Grape-slug, larva of numerous cnouo-h, taking" the folia8:e com- 

7iocampa pygmcza. ° 

pletel}-. Many other cultivated plants, in- 
cluding the strawberry, are attacked bv these saw-fly lan^se : but 
their habits are very similar, and the remedies to be adopted 
against them are also verv much the same. 

The largest of our American species, Cii/ibex americojia. is 
found on willow, sometimes in considerable number, as a pow- 
dery, whitish lan'a an inch and a half in length, with a broad 
dark stripe on its back. 

Experience has shown that all these species are very suscep- 
tible to the influence of white hellebore, and that e\'en a small 
quantity is quickly fatal. Infested plants can, therefore, be 
cleared in a few hours by a thorough drenching with a decoction 
of white hellebore, used at the rate of one ounce in one gallon of 
water ; or the plants may be dusted with the powder, undiluted 
or mixed with several times its owm bulk of cheap flour. Any 
stomach poison — e.g. , the arsenites or tobacco — will answer as 
w'ell as hellebore, while on the slimy types even fine road-dust 
will quickly choke them to death. Air-slaked or dr}- hydrate of 
lime burns through them in less than an hour when carefully ap- 
plied. These insects are so easily killed that it is the fault of the 
farmer himself if he suffers injur}^ 

The '''horn-tails" resemble the ''saw-flies" in away, but the 
character of the ovipositor is different and rather more like an 
auger or borer than like a saw. So, too. the species are, as a 
rule, internal feeders instead of eating openly upon the foliage. 
The larvae are usually slender, white or nearly so, and in- 
fest plants ranging from the stems of wheat to the trunks of 



THE INSECT WORLD. 



375 



trees. Some forms live in blackberry and raspberry canes, 
others in grasses ; I have taken a species from alder, and in 
fact a very large number of plants are infested by these boring 
Hymenoptera. The largest of our species is the ' ' pigeon Tre- 
mex, ' ' T. columba, the larva of which attacks quite a consider- 



FiG. 430. 




Pigeon Tremex, T. columba. — a, larva, with young larva of Thalessa fastened to its 
side ; b, its head ; c, d, female and male pupae ; e, female. 

able variety of trees, including maple, elm, hickory, and beech, 
and bores into the solid wood, usually when the tree is beginning 
to die, or is even dead, but not decayed. 

Dealing with these insects is always rather a difficult matter, 
- because we have no means of getting into the infested plants with 
insecticides. We are again reduced to farm practice, and must 
arrange our methods of cultivation in such a way as to reach and 
destroy the insects by depriving them of food. Thus, with the 
Phylloecus infesting blackberry, if the canes are topped about 
midsummer, or a little before, the larvae never mature, because 



376 



AJV ECONOMIC ENTOMOLOGY. 



Ftg. 432. 



the wood dries, becomes unsuitable for food, and, as the insect is 
incapable of travelling, it starves to death. 

In the case of Cephus pygjficsiis, the insects boring in wheat, 
they spend the winter either low down in the infested stalk — i.e., 

in the stubble — or in the soil just 
below the surface, in either the 
larval or pupal condition. The 
proper remedy is to burn the 
stubble as soon after harvest as 
possible, or to plough it under 
deeply. This destroys the in- 
sects and results in preventing 
injury the year following. We 
have no means of reaching the 
larva while it is actually working 
in the stem of the plant. The 
remedy is radical, and were it 
universally resorted to, would 
need to be applied only at inter- 
vals of several years. 

The "gall-flies," belonging to 
the family Cynipidcs, are curi- 
ous creatures. They resemble 
minute wasps in form, and gen- 
erally have a very short, chunky 
body, which is often compressed 
and joined to the abdomen by a very slender petiole or stalk, 
in sharp contrast to the species heretofore written of These 
gall-flies are mostly true parasites on plants. They derive their 
common name from the fact that they produce swellings, protu- 
berances, or ' ' galls' ' of great variety on vegetable tissues ; some- 
times on leaves, on twigs, on trunks, or even on roots ; and 
perhaps, of all others, the oak is the favorite of the insects of 
this family, bearing the greatest variety of galls on all its parts. 
I say these insects are mostly plant parasites, and intend to ex- 
press by this that they do not actually eat the infested vegetable 
tissue. The irritation caused by the larva induces an abnormal 
growth in the part of the plant infested, and in a cell in this 
growth it has its home. Here the insect reaches maturity with- 




Cephiis pygmceus^ wheat-stem saw-fly. 
— a, outline of larva, natural size ; b, 
larva enlarged ; larva in wheat stalk, 
natural size ; adult female ; f, female 
parasite, enlarged. 



THE INSECT WORLD. 



377 



out devouring any part of its vegetable envelope, changes to a 
pupa, and emerges from the gall, leaving it intact, except for 
the hole through which it emerged. It seems, therefore, as if 
certain abnormal plant ex- 
udations secreted in the 433- 
gall form the actual food 
of the larva, and it is a 
curious and interesting fact 
that the same species in- 
variably produces in the 
same place the same kind 
of gall. In other words, 
the appearance of the gall 
is an unfaiHng index for An oak gaii-fly. 

the special student to the 

species that made it. Many interesting problems are connected 
with the study of these gall-flies ; for instance, in some species 
both sexes are present early in the season, but in the second or 
midsummer brood females alone make their appearance. The 

Fig. 434. 





Gall made by the larva of Cynips q. spongifica. — a, larva in its cell ; b, point 
of exit of adult. 

progeny of this female form, which may or may not resemble 
the spring form, in turn produces males as well as females. Of 
other species no males are yet known, and, so far as we have 



378 



AN ECONOMIC ENTOMOLOGY. 



Fig. 435. 



any evidence at present, there is a continuous breeding by female 
individuals only. 

There are only a very few injurious species among these gall- 
flies. Occasionally we find on blackberry stems an irregular, 

warty swelling, and if 
this be cut into, it will 
be found full of cells 
occupied by these little 
Cynipid larvae. This 
kind of gall is known 
as " multicellular," be- 
cause inhabited by nu- 
m e r o u s specimens. 
Similar galls are found 
on the roots of rose 
and plants of the same 
natural family, and in 
a few other cases cul- 
tivated plants become 
subject to gall growths. 
As a matter of fact 
these galls are scarcely 
injurious, because in 
most cases the plant 
continues growing be- 
yond them, or even if 
a shoot is lost, perma- 
nent injury is rarely 
done. Certain species 
of oak-galls produce a 
black stain, and these 
were at one time al- 
most universally employed in making an ink of remarkable per- 
manence. Even yet the law in some States requires for certain 
records an ink of which oak-galls is one of the ingredients. 

It is a small step from parasitism upon vegetation to parasit- 
ism upon animals, and hence it is not surprising to find that some 
species of this family are parasitic on other insects. The differ- 
ences between these forms and the true gall-makers are not easily 




c, Pithy gall on blackbern 
7iebulosus ; b, section to show cells 
pupa. 



made by Diastrophus 



larva 



THE INSECT WORLD. 



379 




a, two-jointed trochanter 
of parasitic Hymenoptera ; 
b, normal structure. 



pointed out, since the insects are usually small in size ; indeed, it 
is a matter of little importance to the farmer, because in any case 
he can look upon these gall-wasps with indifference, and without 
much fear of possible injury to himself 

There is a very large series of parasitic Hymenoptera, and it 
contains a number of families, nearly all the species of which are 
beneficial. To the practised eye a doubt rarely exists as to 
whether an insect is parasitic or not ; but 
that the student may be able to decide 
this matter for himself if he chooses, it 
may be pointed out that the trochanter, 
the little segment between the coxa and 
femur of the leg, is rather peculiarly de- 
veloped here. It is normally composed 
of one joint only in all the bees, wasps, and 
ants, whatever their size or appearance, 
but it is two-jointed in all the parasites. 
This character can be easily seen on large 
specimens with or without a lens, but on 

minute species it becomes more difficult ; and, after all, in most 
cases the farmer is justified in assuming that most of the minute 
wasp-like creatures that he notices are parasites and beneficial. 

One feature characteristic of a great number of species is an 
external ovipositor, or egg-laying tube, and this may vary from 
a scarcely visible projection to an enormously developed hair- 
like appendage five to six or even more inches in length. 

There may be frequently seen on the trunks of various trees a 
quite large ichneumon, a Thalessa, yellow or black in color ac- 
cording to the species, which has its long, bristle-like ovipositor 
forced deep into the wood, and so firmly fixed, occasionally, that 
it is unable to withdraw it, and perishes miserably. Wherever 
this occurs the trees will be found infested by borers, and all but 
universally this ichneumon is accused of being the parent of the 
larva that produces the injury. The circumstantial evidence is 
all against it ; but we really have here a beneficial species which 
is after the wood-boring larva of the ' ' pigeon Tremex. ' ' The 
insects seem able to recognize an infested tree, and pierce the 
trunk until the ovipositor reaches one of the burrows of the wood- 
feeding larva. In this an egg is laid, and the larval parasite, 



Fig. 437- 




Long-tailed ichneumon, Thalessa lunator.—a, larva; b, head of same; c, pupa; d, tip of 
pupal ovipositor; e, female adult; /, tip of abdomen, seen from the side; gy male adult; 
A, tip of abdomen. 



THE INSECT WORLD. 



381 



when hatched, crawls along the burrow until it comes into contact 
with its host. It then punctures the skin and remains fixed to 
the outside, sucking the juices and gradually killing the borer. 



Fig. 438. 




Pimpla conquisitor . — a, larva ; c, pupa ; d, adult ; other references are to structural 

details. 



By no means all of our "ichneumons," even of those belong- 
ing to the family IcJmeumonidcB , have external ovipositors ; yet 
there is a distinctive character in their appearance which is easily 
recognized but hard to de- 
scribe. The species belong- 439- 
ing to the typical genus Ich- 
neumon have rather long, 
slender forms, with flattened 
abdomen and no external 
ovipositor. They are often 
gaudily colored, the antennae 
are frequently banded with 
yellow, and many are metallic 
blue or green. The species 
are usually parasites on cater- 
pillars. One of the largest 
and most frequently noted species is that which infests the larvae 
of the common swallow-tail" butterflies. It is orange-yellow 
in color, with smoky-black wings, the body nearly an inch in 




Tragus exesorius on a chrysalis of Papilio, 
from which it has emerged. 



382 



AN ECONOMIC ENTOMOLOGY. 



Fig. 440. 



length, and the wings expanding fully an inch and a quarter or 
even more. This makes the species easily recognizable, and it 
will serve very fairly as a type of this particular branch of the 
family. Species of this size usually lay only a single egg in the 
host, and in the case of the "swallow-tail," the caterpillar retains 
strength enough to change to a chrysalis ; but from this chrysalis 
there emerges through an ugly hole in the side the Trogus exe- 
sorius, which has just been described. Frequently, however, in 
smaller species, a considerable number of parasitic larvae develop 
in one caterpillar. 

Of quite a different type, as compared with those just described, 
are the species of Ophion. These are large or very large 
creatures, black or honey-yellow in color, and the bodies are 

transversely flattened and 
squarely cut off at the pos- 
terior extremity. They are 
thus blade-like in shape, and 
the ovipositor rests concealed 
in a groove in the squarely 
cut off end segment. Though 
these insects are not stinging 
Hymenoptera, strictly speak- 
ing, yet the ovipositor is so 
short and sharp that the in- 
sects make use of it as a 
means of defence. They 
should be carefully handled, 
therefore ; though the sting, 
if * ' hot' ' for a few moments, 
seems not to be so poisonous 
as that of the bees and wasps. 

In the family Braco7iidcs 
the species are smaller, as a 
rule, — sometimes very small 
indeed, — and all are parasites. The difference between the pre- 
vious and the present family is in the venation, and is not easily 
made out, except by the special student ; nor from a practical 
stand-point is the matter an important one. It is among the 
members of this family that we find many of the minute creatures 




Long-tailed Ophion, Ophion macrtirum, 
larva. 



and 



THE INSECT WORLD. 



383 



that infest aphids. If, at any time during the summer, a leaf 
badly infested with plant-lice be examined, there will be usually 
found a few specimens that seem abnormally swollen and livid 
gray in color rather than green or yellow. Such specimens are 
parasitized, and if they be removed to a closed vessel, there will 
be found in it, in a few days, minute blackish or brown wasp-like 
creatures, and on each of the infested plant-lice will be seen a little 
round hole, which shows where the insect emerged. They are 
usually examples of minute Braconids, and are the most im- 
portant of those natural checks that prevent the increase of plant- 
lice above a certain point. Unfortunately, that point does not 
coincide with the hmit at which the insects become injurious to 
the farmer ; hence, though the parasites accomplish their pur- 
pose, they do not, therefore, confer any direct benefit upon him. 

At almost all periods during the season, but especially late in 
summer or fall, caterpillars may be seen, bearing upon their 
backs and sides white or yellowish, egg-shaped bodies. These 
are often supposed to be the eggs of the caterpillars, but as a 
matter of fact they are cocoons of Microgaster or Apanteles, 
little parasites belonging to this family ; and if the caterpillar be 
confined for a few days it will be noticed that from the tips of 
each of these egg-shaped bodies a little circular lid is lifted off 
and a little wasp emerges. If, late in summer, a number of the 
large sphinx caterpillars infesting potato or grape-vines are 
watched when they yet show no signs of infestation, one may fre- 
quently see the little larvae boring their 
way through the skin, wriggling until 
they have emerged for more than half 
their length, and it is then easy to 
watch the formation of the small silken 

rx-ii -11 1 Sphinx larva covered with Mi- 

cocoons. The caterpillar soon becomes crogaster cocoons, 

an odd-looking sight, with anywhere 

from a dozen to fifty or even a hundred of these little maggots, 
all engaged in spinning cocoons, projecting from it in every di- 
rection. The egg-like cocoons are attached merely by a little 
point, so that they may be easily removed. But the caterpillar 
has been drained of its strength and of the substance for the for- 
mation of the future butterfly : it collapses and dies, unable to 
complete its transformation to the pupal stage. 




384 



AN ECONOMIC ENTOMOLOGY. 



Most of these parasites have the disadvantage of not influ- 
encing in the least the amount of injury done by the host ; they 
simply prevent it from changing to an adult. It often happens 
that spinning caterpillars even complete their cocoon, and in this 
we find the mass of parasitic cocoons instead of the Lepidopter- 
ous pupa. On the other hand, some of them complete their 



Fig. 442. 




Apa7iteles species. — Little mass of cocoons on leaf, replacing an infested larva ; a 
single cocoon below, from which adult has issued ; much enlarged. 

development and kill the caterpillar before it is much more than 
half-grown. Many of these cocoon-forming species belong to 
the genus Microgaste7% and they are typical of a ver^^ large 
series in the family. The plant-lice-infesting forms frequently 
belong to the genus Aphidius. As in the previous family, many 
of these insects have an external ovipositor. 

While the preceding series of parasites contain a very fair pro- 
portion of large species, the next family, Chalcididcs , contains 



THE IXSECT WORLD. 



\Qxy few, except small forms, which are quite usually metallic 
black, bronze, or green. The wings are without venation, except 
for a strong vein running parallel to the costal margin, but not 
reaching quite to the tip, and 
the antennae are geniculated 
or abruptly bent at the end 
of the long first joint. Few 
of these have the ovipositor 
visible, and usually it lies in 
a groove on the under side 
of the tip of the abdomen, 
issuing before the apex. These 
Chalcidid flies are exceedingly 

. . Aphehnus mytilaspidis , parasite on scale 

numerous, and are parasitic on insects ; much enlarged, 

a great variety of other insects. 

They are rather more robust in build than the other small para- 
sites, and this fact, with their usually brilliant metallic coloration, 
is a tolerably good guide to the family, of which the species in- 
festing the common cabbage butterfly may serve as a good 
example. If, early in the spring, a large number of chrysalids 
of the cabbage butterfly be collected, — which can be easily done 
along the fences bordering last year's cabbage-field, — it will be 
found that some of them have a rather warm gray color and 
move the joints of the abdomen freely, evidently showing life. 
Others will have a peculiar, dead, straw-yellow color, and the 
abdomen is brittle and will break rather than move. If it does 
break, the interior of the chrysalis will be found completely filled 
with little, greenish-gray, maggot-like larvae, in which the seg- 
ments are well marked and a little darker in color. If such 
infested chrysalids be removed to a warmi room and kept in a 
covered vessel, there will emerge in due time dozens of Ptey-o- 
malus puparum, a greenish-bronze Chalcidid, instead of the 
common white cabbage butterfly. 

Though these insects are minute, being scarcely one-eighth of 
an inch in length, yet they are giants compared with others 
which live in scales and even in the eggs of other insects. Very 
frequently such Chalcidids are bred from galls, and they are here 
either parasitic upon the actual gall-maker, or they may live in 
the abnormal tissue produced by the Cynipid larvae. We find 

25 




386 



AJV ECONOMIC ENTOMOLOGY. 



the little fellows everywhere, infesting almost all kinds of insects, 
and undoubtedly they do much to prevent the increase of injuri- 
ous species. Especially is this true of those ovipositing in eggs 
of other forms, for they are then "nipped in the bud," so to 
speak. Their work in the destruction of scale insects is also of 
great importance, and frequently we find on a scale-infested tree 
a large proportion with little round holes, showing where a para- 



FiG. 445. 




Trichogramma pretiosa, a parasite in insect eggs ; a Female Isosonia oviposit- 
dot may represent natural size. ing in stem of wheat. 



site has emerged. It is a pity that in a family so generally useful 
we should find, exceptionally, some injurious species ; but there 
is no doubt that members of the genus Isosoma lay their eggs in 
the stems of grasses, including w^heat, and the larvae, working as 
they do in the joints, have received the name "joint-worms." 
The stem hardens where the larva punctures it, and this inter- 
feres with the nourishment of the plant above that point, les- 
sening or entirely preventing the formation or maturing of the 
grain. There is but a single annual brood of these insects, and 
the winter is passed in the straw, from which the adults emerge 
in spring. In localities where this insect is sufficiently abundant 
to make it necessary to use remedial measures, the utilization of 



THE IX SECT WORLD. 



387 



the straw during the winter will check injury to a great extent. 
It is certain that some near alhes of Isosoma and perhaps some 
other genera of Chalcidids are, at least in part, vegetarians ; 
but, so far as I am aware, none other has proved in any true 
sense of the word injurious to cultivated crops. Hence, although, 
especially in the central and western parts of the United States, 



Fig. 446. 




Isosoma tritici. — a, b, larva ; /, adult female ; g, fore-wing ; A, hind wing ; other letters 
are structural details. 



the ''joint-worm" may do some damage, yet it is so easily con- 
trolled that it scarcely affects the value of the family as a whole. 

The smallest of all our parasitic insects belong to the family 
Prodotjypidce , and even the largest of them would be ordinarily 
considered as small insects. Among them we find the greatest 
number of egg parasites. As compared with the Chalcidids, 
these insects are rarely metallic in color, usually black or brown, 
sometimes yellow, and much more slender in build ; the body longer 
in proportion to the thickness. Their habits may be said to be in 
general like those of the other parasites, and they are not easily 
distinguished from them, except by the special student ; but they 
rarely have the geniculated antennae described for the Chalcidids. 
None of these Proctotrypids are injurious, so far as we know, or 
feed on vegetable matter, though some are found in galls, appar- 
ently parasitic upon the original gall-maker. 

Taken as a whole, the parasitic Hymenoptera belonging to 



388 



AN ECONOMIC ENTOMOLOGY. 



the various families heretofore mentioned constitute one of 
nature's means of keeping within bounds the insects of other 
orders, and, indeed, the various parasites themselves. Not only 
are the little creatures parasites upon almost all other insects, 
but as a matter of fact they are parasitic even upon each other, 
or hyperparasitic, so that it is a clear case of "dog eat dog." 



Fig. 447- 




Ceraphron triticutn, parasitic in wheat plant-louse. 



They undoubtedly check injurious species, but also each other ; 
in this way preserving a balance from year to year which keeps 
all the forms at about the same relative level. Of course the 
" hyperparasites," as the forms infesting the other parasitic 
species are termed, are distinctly injurious from the agriculturist's 
stand-point ; perhaps even more so than the forms actually feeding 
on vegetation. 

The question of making economic use of parasites belonging 
to this order has been frequently discussed, but no practical 
results have yet been obtained. Occasionally several species 
attack a single host, and yet, withal, they seem to produce no 
effect upon it in the long run. Even though we may breed out 
of a lot of caterpillars more parasites than butterflies or moths, in 
the season following the caterpillars will be just as abundant as 
they were the year before. Just where the checks to parasite 



THE INSECT WORLD. 



389 



increase come in is not entirely clear in all cases. Take, for 
instance, the cabbage butterfly already spoken of. I have, in 
collecting chrysalids in spring, found scarcely one in twenty that 
was living, and from which I obtained a butterfly. All the others 
produced parasites, chiefly the little Chalcidid already spoken of : 
hundreds of them for every butterfly ! It would seem, then, as 
if there were parasites enough here to attack every caterpillar 
that hatched from the eggs of this first brood ; yet somehow 
they seem to be almost entirely free, and the butterflies increase 
normally until after midsummer. It seems almost impossible, in 
fact, to get a parasitized larva until August or September, and not 
until we get the last brood of caterpillars do the parasites seem to 
resume activity, after all the injury has been done to the cabbage 
crop. Perhaps ninety per cent, of all the caterpillars will be 
found infested at this time, and a mere fragment of the brood 
comes to maturity the following spring. 

We are unfamiliar with the complete life history of most of 
these little species, and, indeed, a great many yet remain to be 
described. It would be rash to say that we can never use them 
for our own purpose, — that is, in checking injurious species ; but 
if so, it is certain that we must know very much more about 
them than we do at present. 

A very curious creature sometimes found flying through open 
woods is the Pelecinus polytiirator, for v/hich the family Pelecin- 
idcB has been established. The female is remarkable for the length 
of its slender abdo- 
men, each of the joints Fig. 448. 
being almost as long 
as the head and body, 
and the entire insect 
is sometimes nearly 
four inches in length, 
the abdomen alone 
- measuring more than 
three. The insect is 

so very odd and so Pelednus polyturator, male and female. 

often noticed that it 

is mentioned here to answer a frequently asked question as to 
its character. It is not at all rare in some localities, but its habits 




AN ECONOMIC ENTOMOLOGY. 



are yet unknown to us. It is believed to be parasitic, but upon 
what sorts of species no one has yet discovered. 

The remainder of the order has been roughly classed as 
Aculeate^ or " stinging" forms, the majority of the species being 
provided with an ovipositor modified into a sting like that of the 
bee, having connected with it a more or less well-developed 
poison-sac. From the fact that the sting is a modified ovipos- 
itor, or egg-laying tube, it follows that it can be found in the 
female only ; hence the males of bees and wasps of all kinds 
have not the power of stinging, and may be safely handled. The 
use of the sting varies in the different families, and this subject 
will be further spoken of. 

One little group is separated off under the title " Tubulifera," 
and contains the single family Chry sididcB , bees of a brilliant 
metallic blue and green, deeply punctured or pitted, and, as a 
whole, of rather robust build. They are 
Fig. 449. among the most beautiful of all the Hy- 

fnenoptera^ are of fair size, and are peculiar 
in the structure of the abdomen, which is 
telescopic. From three to five segments 
only are visible, the others being re- 
tracted, but capable of a tube-like exten- 
sion, at the end of which the minute sting 
is situated. They have been called 
"cuckoo-bees" from their habit of laying eggs in the nests of 
other solitary bees and wasps. The larva is supposed to hatch 
before the true owner of the food supply, and to devour the 
store, leaving the other hapless baby to starve to death. Eco- 
nomically, the species are of no importance, save as they form a 
check to the increase of certain other bees and wasps. 

Few insects are better known to the average observer than the 
ants that are found everywhere : in our houses, in fields, in 
woods, in the ground, under stones, in trees, in roots, and in all 
other likely and unlikely places. They are abundant in temper- 
ate countries, more rare to the northward, but become veritable 
pests by their enormous numbers in the tropics. They have 
many peculiarities of habit, and their development is remarkable 
in certain directions. We find among them architects and 
builders, agriculturists, masons, tailors, and many of the other 




THE INSECT WORLD. 



391 



trades and professions are represented. We find communities 
governed in some directions despotically by a queen, yet at the 
same time forming the most perfect republic, in which every indi- 
vidual has its rights firmly established and absolutely beyond the 
control of the nominal head of the colony. We have organiza- 
tions that make war, keep slaves, lay in stores, and provide for 
contingencies ; they seem able to forecast the future in some 
directions and intelligently provide for it. In other words, they 
offer some of the most interesting problems that can possibly be 
studied. It is unnecessary to waste words in describing the ap- 
pearance of an ant, and it need only be said that all the true 
ants are distinguished from the other Hymenoptera by the posses- 
sion of one or more scales or nodes on the petiole or stalk of the 
abdomen. We find also, in this series, the development of what 
are known as "neuters," or workers, —that is to say, female indi- 
viduals in which the sexual characters are not perfected, which 
are incapable of reproduction, and whose function in the nest is 
simply to perform the mechanical labor necessary to keep up the 
colony. These workers have no wings, and in their appearance 
and tlie relative proportion of the parts they frequently differ 
considerably from their parents. There are sometimes several 
forms of workers found in nests, differing from each other in the 
development of certain parts for special purposes, but attention 
will be called to these hereafter, where necessary. Though the 
ants agree in their general habits and peculiar social organization, 
yet no less than five different families have been recognized, 
based upon structural characters, principally of the abdomen and 
head. 

The most numerous in species of these families, containing 
most of our common forms, is the Formicidcs, in which the 
petiole is formed of a single joint only, and the abdomen is 
smooth, without constriction between the segments. In this 
family the "queens," or females, have no sting. They build 
their nests in all sorts of localities. We find them commonly in 
our fields; often in woods, where the large black "carpenter 
ants' ' are the most prominent ; while some occur under stones 
or around the roots of trees. It would be easy to write a book 
on ants alone, but necessarily our notes of them must be con- 
fined here to the features of economic importance. And first 



392 



AN ECONOMIC ENTOMOLOGY. 



let us have their general life history. In a colony of ants, how- 
ever large, there is usually a single "queen," or female, the 

nominal head of the estab- 
lishment, and she attends to 
the business of laying the 
eggs, which are white, cylin- 
drical, and a little elongated. 
They are taken in charge by 
the workers, cared for, and 
in about a month — the time 
varying with the species — 
helpless grubs are produced. 
These are carefully tended 
and fed, because absolutely 
unable to help themselves, 
are periodically cleaned and 
moved about from place to 
place in the nest, that they 
may have the proper degree 
of warmth and dryness or 
moisture, and after about six 
weeks of this coddling they 
are full-grown. Then they 
either spin an oval cocoon, 
in which they change to 
pupae, or change directly 
without forming such a cov- 
ering. The cocoons are cared 
for as tenderly as were the 
larvae themselves, and, these 
are what is usually known as 
' ' ants' eggs. ' ' They may be 
found at midsummer, or thereafter, in almost any colony of ants, 
and usually in the upper chambers of the nest, where they get a 
full supply of warmth from the sun. The adults hatch from these 
cocoons late in summer, and at once take part in the work of the 
nest, so far as they are workers. Of the latter there may be 
two forms, known as "worker minors," or small workers, and 
" worker majors," or large workers, each with different duties. 




Creynastog aster lineolata. — a, b, large 
worker ; c, its head ; d, female ; e, its wing ; 
f, small worker. Family FormicidcE. 



THE INSECT WORLD. 



393 



There are also two kinds of winged forms, males and females, 
both larger than the workers, and the females considerably larger 
than the males. All the insects work their way down to the 
lower levels or inmost galleries of the nest on the approach of 
cold weather, and hibernate in the adult stage in a dormant con- 
dition. In spring, with the approach of warm weather, activity 
is resumed, and, usually some time during the early part of the 
season, on a particularly bright, warm day, the newly developed 
males and females leave their old home and swarm." By this 
is meant that they leave the nest in which they were hatched and 
fly about for a short time. They mate soon after, and are then 
ready to start colonies of their own. None of them ever get 
back to the old home, and if they do not succeed in founding a 
*' hill," they perish in the course of a day or two. Exactly how 
the different species start their colonies is not known, but in some 
cases, certainly, the impregnated female strips off her wings and 
starts a small nest in some convenient place, doing the best she 
can under the circumstances, and laying only a few eggs. These 
she brings to maturity, and they are usually of the small or 
''worker minor" type. When fully developed, these relieve 
their parent from further mechanical work, increase the size of 
the nest, and gather food as well as attend the young that are 
still continually hatching. If circumstances favor, the nest grows 
rapidly, and it may eventually become enormous in size, con- 
taining millions of individuals, and ramifying for distances that 
we have not yet succeeded in following to the end. The life cycle 
of all the ants has not been definitely determined as yet, but 
' ' queens' ' have been kept as long as seven years and workers for 
three or four. The food of ants is variable, — sometimes animal, 
sometimes vegetable, and quite usually both. The same species 
may feed upon fragments of insects and other animal matter, and 
also upon plant tissue of various kinds. They are usually fond 
of Hquid food, especially if it is sweet, and some species gather 
^ and store honey like the bees, although in quite a different man- 
ner. In the more temperate parts of the United States ants 
are only indirectly injurious, although they are never beneficial. 
There is quite a common belief that ants destroy the plant-lice 
among which they are frequently found ; but this is exactly con- 
trary to the fact, for plant-lice play a very important and curious 



394 



AN ECONOMIC ENTOMOLOGY. 



part in the economy of certain species of ants. As we learnt in 
the chapter on plant-Hce, these insects are furnished with a pair 
of honey-tubes near the end of the abdomen, through which there 
is excreted a sweet, almost transparent, liquid, of which the 
ants are very fond. In many cases aphids live on the roots of 
plants during the whole or a part of their life, and such species 
are in nearly every instance carefully tended by ants. We may 
find, on lifting up a large stone at the foot of a tree near the 
edge of a wood, that all the little rootlets covered by it are clus- 
tered as thickly as possible with plant-lice, and that around them 
the earth has been carefully tunnelled out ; in other words, we 
have the roots forming part of the nest system of an ant colony. 
As the plant-lice increase in number, additional roots are laid 
bare, and the young are transported to them that they may 
always find an abundance of food. In return, the ants, whenever 
the desire seizes them, call upon one or more of the aphids, and, 
by touching them with their antennae, induce them to give up 
a drop or two of their sweet secretion. Exactly how large a 
proportion of the food of the ant colony this kind of material 
forms is yet undetermined ; but certain it is that plant-lice con- 
stitute a very important element in the supply of some species, 
and fully represent our cattle for all ant purposes. 

Little brown ants about three-sixteenths of an inch in length 
occur very abundantly in the fields throughout almost all parts 
of our country, building small underground nests. These ants 
belong usually to the genus Lasiiis, and may be found, especially 
early in the year, on the leaves of all sorts of plants infested by 
aphids. In melon and sweet potato fields they are often ex- 
tremely abundant, and it is more than likely that they are active 
in transporting from one plant to another the lice infesting these 
particular crops. Of the Lasiiis brimneus, we know that it tends 
the corn-root louse, gathering the young larvae in the fall and 
preserving them during the winter safe beyond the reach of any 
natural enemies, colonizing them in spring upon the roots of corn 
plants. Indirectly, therefore, these ants are decidedly injurious 
through their relation to the plant-lice. Other species gather 
plant-lice eggs and care for them during the winter, colonizing 
the young upon proper food plants in spring. 

We find certain other species making their hills in our lawns 



THE INSECT WORLD. 



395 



and gardens, or in grass-plots, and they are sometimes decidedly 
troublesome in such localities. Where this occurs, there is noth- 
ing better for getting rid of them than bisulphide of carbon. Pour 
a quantity into each of the openings of the disk or hill, closing 
them up by stepping on each as it is treated. The fumes will 
penetrate the chambers in every direction, and if a sufficient 
amount has been used, will kill not only all the adults, but all 
larvae as well. A single application is usually all that is necessary ; 
but in a very large colony it may sometimes happen that the 
farther chambers are not reached by the fumes, and that the nest 
reappears near by ; rarely in the old spot. When that occurs, a 
second treatment is tolerably certain to be effective. It has been 
recommended that, to get the best results, holes be poked with a 
stick into different parts of the hill, but I have not found this of 
any great advantage. It has also been recommended that, after 
pouring a considerable quantity — say three or four ounces — into 
the main opening of the nest, the vapor be exploded by means 
of a match held at the end of a stick. When this is done the 
nest is completely wrecked, and the poisonous vapor is forced to 
every portion of the galleries, so that escape is almost impossible ; 
while larvae and pupae are buried so thoroughly that they can 
never make their way to the surface, even if not killed by the 
fumes. This is a very good method where a large nest is to 
be dealt with ; but whoever attempts it must remember that the 
vapor of the bisulphide is exceedingly inflammable, and must 
make certain that he is far enough from the opening of the nest 
to prevent being caught by the flash. Ants are never desirable 
in a cultivated field ; they have no business there, and are cer- 
tainly of no benefit to the farmer, even if they do not directly 
feed upon plant tissue. 

Wherever the corn-root louse is injurious, late fall ploughing 
should be practised to destroy the nests of the ants. If the 
ploughing be done before the ants have gone into winter-quarters, 
* they will either build a new nest sufficient for their purpose, or 
will move with their belongings to a spot in which they are able 
to winter ; so no good will be accomplished. If the ploughing 
be deferred until frosty nights and cool days discourage activity, 
the ants will be unable to repair damages, or will not have suffi- 
cient time to re-establish themselves before they become torpid. 



39^ 



AN EC 0X0 MIC EXTOMOLOGY, 



The ploughing should be deep and as thoroughly done as pos- 
sible, so as to not only disturb and break up the nests com- 
pletely, but to scatter the plant-lice, eggs, or other material that 
the ants may have gathered. By this simple means injury may 
frequently be prevented during the year following. 

Incidentally it has been mentioned that some species of ants 
gather honey and store it ; and, curiously enough, instead of 
building cells for its reception, as do the bees, a special form of 

Fig. 451. 




Honey-ants, Myrmecocystus melliger, filled with honey. 



worker is developed, with an unusually elastic crop and abdo- 
men. These specimens are simply stuffed by the other workers 
until they become of the size of a small cherry, utterly helpless 
and incapable of motion. In this condition they cling to the 
walls of the nest until, in the course of time, their stock is used up, 
when they again resume activity. 

Three of the other ant families to which reference has been 
made contain no species of particular interest to the farmer, how- 
ever interesting they may be to the student. 

But in the family Myrmicidce we again find species that are 
numerous and of more or less importance to man. Here the 
petiole of the abdomen is tw^o-jointed, differing thus from the 
other important family, Formicid<z. Many of the species have 
the sting well developed in workers and " queens," and are for- 
midable creatures by reason of this weapon ; but not all our forms 
are so furnished, as is known by those who have suffered from an 
invasion of small red ants in houses. This little creature, Mono- 
morium pharao7iis, sometimes occurs in myriads, and nothing is 



THE INSECT WORLD. 



397 



safe from it. Sugar is especially attractive, but almost anything 
is attacked, nothing more readily than a bone from which the 
meat has been roughly scraped, and which is yet a little bloody. 
It seems impossible to get rid of these creatures, because they 
avoid poisoned food and anything that has 
the appearance of a trap. A few specimens Fig. 452. 

may be killed, but very soon the character 
of the mixture is recognized, and it is left 
untouched. " Insect-powder" — pyrethrum 
— is effective, but it is practically impossible 
to get it everywhere, and the ants simply 
avoid it. Carbolic acid and naphthalene are 
both useful as repellents : the insects dislike 
the odors intensely, and will not approach 
these materials ; but while certain closets may Monomorium pharaonis. 
be protected in that way, the odors are not 
particularly desirable near food products, and are as repugnant 
to many persons as they can possibly be to the ants them- 
selves. The simplest method, perhaps, is mechanical destruc- 
tion, as follows : Where meat is used every day, the bones, or 
some of them, should be cut out before it is cooked and placed 
in a main line of insect travel. When they become thoroughly 
covered with hundreds or even thousands of ants, the whole mass 
should be thrown into the fire. If this process is repeated two 
or three times a day, a few days in succession, the ants seem to 
be seized with a panic, and usually abandon the house com- 
pletely. Instead of bones, a sponge dipped in sugar water and 
loosely pressed out may be used ; or, better yet, there should be 
two sponges. The sweetened one should be placed where the 
ants run, and the news of its presence will spread throughout the 
entire house in a remarkably short time. When the first sponge 
is entirely filled with ants, the second should be prepared in the 
same way to replace the first, which is to be taken up and put 
into boiUng water. This destroys the insects at once, and the 
sponge can be washed out, again dipped in the sugar water, and 
used to replace sponge number two when that is filled with in- 
sects. Here the same effect is obtained : the insects are seized 
with terror, and seem to realize the presence of a force that 
they do not understand. The sudden lessening of their numbers 




398 



A.V EC 0X0 MIC ENTOMOLOGY. 



strikes them with such horror that they abandon not only their 
nest but the house itself. I have myself used this method on 
two occasions, and have recommended it frequently to others ; 
in every case with the best results. 

To this family belong the so-called "agricultural ants" of 
Texas and the Southwest, some species also occurring in Florida 
and other parts of the Southern United States. These build im- 
mense underground nests, and keep on the surface a cleared 
space varying in diameter according to the size of the colony. 
They cultivate grasses on these plots, of the seeds of which they 
are especially fond, and which they store in their galleries. Their 
food, in fact, consists mainly of seeds of various descriptions, 
and these they gather from whatever plants there may be in the 
vicinity. The insects are very abundant in some localities and 
are great nuisances in cultivated fields, not so much from what 
they actually destroy by eating, but from the fact that they tol- 
erate nothing in their vicinity except what suits them. They 
have no particular use for corn or cotton, and ruthlessly cut 
down every stalk that encroaches on their domain. The only 
substance that has been employed against them with any degree 
of success is bisulphide of carbon, and this should be used in 
quantities depending upon the size of the nest. In these cases 
the vapor should be exploded in order to produce the best re- 
sults. The nests extend for so long a distance underground that 
the insects will not be reached otherwise, and when the material 
has entirely evaporated, the galleries are again useful to them. 
On the other hand, the explosion shatters the entire nest, and 
the insects that escape in remote galleries are not likely to start 
again on the same soil, unless the queen also has escaped. It 
has been already indicated that such a nest is a complicated or- 
ganization. It contains not only its owners with all their races 
and castes, but frequently also slaves, — other species of ants that 
have been conquered and stolen while in the larval or pupal 
state, and which now perform all or a great portion of the manual 
labor of the colonies. It often contains also not only plant-lice, 
but coccids, which are cared for in the same way, and occasion- 
ally other species of Homoptera, such as tree-hoppers. We 
find, in addition, numerous species of insects that seem to take 
the part of guests. Some of these are scavengers, and they evi- 



THE INSECT WORLD. 



399 



dently keep the nest clean and remove decaying particles ; others 
may be of some use to the ants by excreting certain sweet sub- 
stances which induce their toleration ; while yet others have no 
use at all, so far as we can discover. Such are certain crickets 
which are always found associated with ants, and certain cater- 
pillars. What functions these insects have in the ant-hills is as 
yet somewhat obscure. 

In the tropics there are species that occasionally change their 
camps, and are known as foraging ants. When the whim seizes, 
or unknown causes determine them, they leave their nest, bag 
and baggage, attended by all the insects that lived with them, 
and start upon a march straight forward, destroying everything 
that attempts to prevent their passage. A house or a village is 
no barrier ; they pass through or over it, destroy every living 
thing it contains, and devour all the provisions. The inhab- 
itants of countries subject to these foraging expeditions soon 
learn to recognize their character, and immediately seek safety 
in flight. The ants continue their march, and soon the house 
or village can be reoccupied, with the certainty that, if all the 
provisions have been cleared out, so also have all the vermin : 
rats, mice, snakes, roaches, and similar creatures being all killed 
and eaten. 

The battles of ants have been described by more than one 
author ; but as this is the function of another kind of work, 
nothing more will be said here about these very interesting 
creatures. 

Next in the orderly series come the Fossores, or ' ' digger- 
wasps." Here the two normal sexes only are developed, and 
they are solitary, — that is, they never form communities. They 
often build their nests underground, preferring sandy spots ; but 
the families vary much in this respect. The females are always 
provided with a sting, which they use on slight provocation, and 
they differ from the next family of true wasps by having the 
wings always flattened and never longitudinally folded in repose. 
Sometimes, instead of burrowing underground to form their cells, 
they use the stems of pithy plants like alder and sumach, and 
often nests are built of mud, in sheltered localities against houses, 
barns, or other convenient places, or even attached to twigs or 
shrubs. 



400 



AN ECONOMIC ENTOMOLOGY. 



Fig. 453- 




A velvet ant, SphcBr- 
ophthalma occiden- 
talis. 



Occasionally we find, running on sandy spots, an insect that 
looks like a large ant, very prettily colored and banded with 
bright scarlet and black, rusty red or mottled yellow. If one of 
these apparent ants be picked up, the result 
is usually a surprise in the form of an enor- 
mously long sting, for we really have a wing- 
less "digger-wasp," which from its appear- 
ance and habits has been called a ' ' velvet 
ant." Just what the breeding habits of these 
Mutillidcs are is not known, but they are sup- 
posed to be parasites, or at least to lay their 
eggs in the nests of other species of Hymen- 
optera. There is considerable difference be- 
tween the sexes, and the males are winged 
even when the females are wingless, the wings 
being usually blackish in color. 

Another series of "diggers" belongs to the 
family ScoliidcB, and these may often be seen 
quite early in the spring, flying close to the 
surface of the ground, with a buzzing noise. Often they are 
found visiting flowers, particularly the males, which are some- 
times quite abundant when raspberries are in bloom. These in- 
sects, so far as we know 
Fig. 454. their habits, lay their eggs 

in underground larvae, 
which are then devoured 
by the young of the wasp. 
The common "white 
grub," the larva of Lack 
noster?ia, is subject to the 
attacks of one of these 
species, Tiphia inornata, 
a black wasp, rather sparingly clothed with fine white hair, and 
sometimes attaining the length of three-fourths of an inch ; and 
there are others that attack our injurious underground species of 
all orders. 

In the family PompilidcB we have a series of rather stout, 
black forms, quite frequently banded with red on the abdomen, 
while sometimes the entire insects are more or less red. They 





O or 

White-grub parasite, Tiphia i-iiotmata. — a,\ 
go; head of larva ; c, larva ; d, cocoon 



THE INSECT WORLD 401 

usually have a velvety appearance, or look as if they were cov- 
ered with a whitish bloom, and the wings are also either black or 
yellow, like the prevailing colors of the body. They lay their 
eggs in spiders, which they bury, and in which the larvae de- 
velop. Perhaps this is a good place to mention the fact that 
these digger-wasps make use of their stings and the poison se- 



FiG. 455- 




Pepsis formosus, tarantula-hawk. 



creted by them for preserving from decay and in a condition 
suitable as food for their young the larvae, spiders, and other 
insects upon which they feed. They sting their prey very care- 
fully, in such a way as to paralyze and render it motionless, 
while yet it does not die ; and the larvae, when they hatch, begin 
feeding very carefully, so as not to kill their host until they them- 
selves are sufficiently developed. The poison introduced seems 
. to simply suspend life, or rather allows it to go on without a 
waste of tissue. Spiders of all kinds are attacked, and even the 
fierce tarantula of the South and Southwest has its enemy in an 
enormous species oi Pepsis known as the "tarantula-hawk." 

Perhaps the most common forms belonging to this series are 
those in which the abdomen ends in a small bulb-like structure 

26 



AN ECONOMIC ENTOMOLOGY. 




connected with the thorax by means of a long stalk or pedicel. 
These belong to the family Sphecidcs, of which the majority 
build their nests underground and provision them with spiders, 
caterpillars, or other larvae. Others, known as " mud-daubers," 
species of Pelopoeus, plaster their nests against out-houses, in all 

sorts of corners and under all sorts of 
Fig. 456. shelters. They are sometimes built 

singly, but usually in groups, and may 
consist of either a shapeless mass of 
mud, or may be regularly arranged, 
often with ribbed sides. The insects 
that build these nests are either metal- 
lic blue, or black marked with yellow, 
and here the pedicel connecting the 
abdomen with the thorax is unusually 
A mud-dauber, Peiopcus ^ A^rv^^x, The mud is Carried 

species. 

by the insect with its forelegs and jaws, 
and is appHed carefully, pellet by pellet, to the nest, until the 
cells are completed. Then they are stored with some one kind 
of insect as food for the larva. If the insect begins on caterpillars, 
it continues to collect caterpillars, all of the same species, stinging, 
as already described, so as to paralyze them, and then packs 
them away in the cavity as closely as possible. Finally, when a 
cell is full, an egg is introduced ; and now, when the young wasp 
hatches, it finds food in abundance at hand, and simply lives upon 
this supply, taking one caterpillar after another, or one spider 
after another, as the case may be. Some small species store their 
nests with plant-lice. These insects are to be considered as de- 
cidedly beneficial, and if the nests are sometimes unsightly and 
the wasps themselves a nuisance, yet, taken all in all, they deserve 
encouragement. The number of caterpillars destroyed by them 
in the course of a season is enormous. I have counted thirty 
canker-worms in a single cell, and have sometimes opened nests 
in which there were an even greater number of small Tortricid 
caterpillars. Any insects which destroy as many caterpillars as 
do these wasps deserve our best consideration and should not 
be wantonly destroyed. Another peculiarity to be noticed in 
opening the nests is, that the insects, whether caterpillars or 
spiders, are all of just about the same size, as if the mother had 



THE INSECT WORLD. 



exercised great care in portioning out the food to the best ad- 
vantage. The adults may often be found on flowers, and when 
the golden-rod is in bloom in late summer, some of our largest 
and most attractive species, X^^^ Sphex ichneumo7iea, make their 
appearance in great abundance. 

The aUied " diggers" belonging to the Larridce have the 
abdomen more closely joined to the thorax, and provision their 
nests, which are made underground, with small grasshoppers. 
The insects are not nearly so common or so numerous in species 
as those previously mentioned, and are chiefly inhabitants of the 
more southern States. 

In the BembecidcB we have many large, brightly colored spe- 
cies, some of which prey upon cicadas, stinging so as to render 
them helpless, and carrying them ofl" to their nests as provision 
for their young. It is interesting to watch a specimen of Sphe- 
cius speciosus when it has a large cicada to be transported. If 
the insect is captured and 

paralyzed upon a tree, the ^^^* 
wasp drags it along the 
branch to some convenient 
point, and from it flies as 
directly as possible towards 
its nest. Sometimes its 
strength is not sufficient to 
sustain the weight, and 
then it is drawn gradu- 
ally to the ground. In 
such case it again drags the 
insect to the top of some 
convenient shrub or tree, 
and makes another eflbrt, 
again flying as far as pos- 
sible before allowing itself 
to be pulled down, but always arranging matters so that it is able 
to make a new start from an eminence. In other words, the wasp 
is often unable to lift the cicada from the ground in direct flight, 
but is able to drag it to an elevation sufficiently great to fly a con- 
siderable distance before being drawn to the ground, and in this 
way, after a time, it manages to reach its nest. These Bembecids 




Sphecius speciosus carrying a cicada to its home. 



404 



AN ECONOMIC ENTOMOLOGY. 



are quite numerous, and the abdomen is conical in shape, con- 
nected with the thorax by a very short and slender neck, or 
pedicel, more resembling the true wasps than any other of the 
species that we have been considering. 

There are several other families with similar habits, differing in 
appearance to some extent, and varying in the character of the 
insects used in storing their nests. Among the families contain- 
ing the smaller species we find those types that burrow in pithy 
plants and prefer small insects for provisioning their nests : — 
flies, plant-lice, and small spiders being the most usual suppHes. 

Taken as a whole, all the digger-wasps are useful insects, and 
they require for food, in the course of a season, a very large num- 
ber of specimens injurious to plant-life. 

The "true wasps," or Vespidcs, are distinguished from the 
' ' diggers' ' by the fact that the fore-wings are folded longitudinally 
when at rest, and this is a character easily seen and quite distinctive. 
We have among them solitary and social forms, — the solitary 
types so called because only the two normal sexes are present, and 
because they do not live in colonies. There is a great variation 
in habit, and we find species that bore in woody tissue, some 
that inhabit pithy plants, some that burrow in the earth, and 

others that make mud 
nests. The mud nests 
vary in form and are 
often quite pretty, those 
of Eumenes resembling 
a jug or vase attached to 
the twigs and stems of 
plants. It is not always 
possible to distinguish be- 
tween the cells and nests 
of the diggers and those 

Fraternal potter-wasp, Eumenes fraterna.—a, of the trUC WaSpS, and 
wasp ; b, its cell ; c, same broken open to show the nracticallv it is a matter 
caterpillars stored in it. ^ . , 

oi no importance, because 
the habits of the insects are similar, — that is, they store their 
cells with insects upon which their larvae feed. All solitary 
wasps are beneficial, therefore, and should be encouraged by the 
farmer. 




THE INSECT WORLD. 



405 



In the social wasps we find a step towards the organization 
found in a beehive, sometimes well and sometimes very poorly 
marked ; but in all cases, besides typical males and females, there 
is a worker caste, which, as in the ants and bees, is composed of 
sexually undeveloped females. Briefly stated, the history of 
these wasps is about as follows : Males and females appear in 
fall ; the females are impregnated and live through the winter in 
such shelter as they are able to find ; in the spring, with the ap- 
proach of warm weather and the opening of the flowers, the 
females revive, and at once begin reproducing their kind. They 
start a small nest of only a few cells, and lay eggs in them as soon 
as they are well started. In a few days the larvae hatch ; the 
female increases the size of the cells and adds to them, and to her 
other duties is now added the care of the newly hatched young, 
which must be fed and tended daily. In three or four weeks the 
first larvae become full-grown, and the cells are then capped by 
the mother. In this closed cavity the change to the pupa takes 
place, and in due time an adult appears. This adult is a worker, 
or undeveloped female, and at once begins to help the original 
mother in the work of attending to the brood and increasing the 
size of the nest. Until midsummer, at least, workers only are 
produced ; but then, when the brood of workers is sufficient to 
relieve the stem mother of all necessity for labor, eggs are laid 
that produce sexually complete forms, — males and females, — which 
generally issue during the first days of September. The old 
female now dies, and when cold weather sets in the workers 
and males also succumb, leaving only the impregnated new 
females to live through the inclement season. Of course there 
are many modifications of this general life history, and some colo- 
nies become very much larger than others. In some instances 
the cells seem to be used over and over again, and no more are 
manufactured than is necessary to accommodate the brood. In 
other instances it seems as if the cells are used only once, and 
new ones are built for each individual larva. The locality in 
which the nests are built also varies, although the general char- 
acter of the comb, or cell, is nearly always the same. As a home, 
some species, like the " yellow-jackets," select a little cavity un- 
derground ; some, like the giant Vespa crabro, a hollow tree ; 
some a favorable spot among the branches. Others build un- 



4o6 



AJV £ CO ATOMIC ENTOMOLOGY. 




protected combs in the shelter of a projecting ledge of rock, or 
under the eaves of houses, or even under fence boards ; while yet 
others build their globe-shaped structures openly upon bushes, 
and these are usually termed " hornets." The material of which 
the nest is composed is a sort of wood-pulp paper. The insect 
scrapes a small bit of wood-fibre from an exposed surface, mixes 
it with saliva, kneads it into shape, and then, by means of the 
mandibles and forelegs, spreads it in a thin layer and attaches it 
to the surface at which the nest is to be started. Layer after 
layer of fibre is added in this way until the nest is completed. 

The enormous structures made by 
^^^•462- ^ the "white-faced" wasp, Vespa 

maculata, are excellent examples of 
what can be accomplished by num- 
bers and persistence. As to feed- 
ing habits, these social wasps are 
usually predaceous, but they are 
also fond of sweets, and may often 
be found on flowers, gathering 

White-faced wasp, F../a;«a../a.a. ^Oncy, Or On ripe fruitS, SUckiug 

their juices. We also find them 
occasionally in butcher-shops, and they have a fondness for 
chewing into raw meat and lapping the blood. They feed their 
larvae honey and other plant juices, and also the masticated frag- 
ments of insects. That is to say, they prepare the animal food 
by first chewing into a pulp before feeding it. 

Two types of these wasps are common throughout the United 
States, — the first rather slender, with a spindle-shaped abdomen, 
and usually a more or less red-brown color, often marked with 
yellow. These belong to the genus Polistes, and they build their 
paper combs openly, — that is, without any covering, and sus- 
pended by a single, short, central stalk. The colonies rarely 
become very large, but they are very numerous in most parts of 
the country. 

The true "wasps," or members of the genus Vespa, have the 
abdomen cylindrical, squarely cut off" where it joins the thorax, 
and are very often contrastingly marked with white or yellow, 
occasionally with red or brown on a black ground. These are 
the "hornets" and "yellow-jackets," and their colonies some- 



THE INSECT WORLD. 



407 



times become of enormous size, many hundreds of individuals 
being found in a single nest in the latter part of the season. 
Durability is not looked for by the insects, and the winter storms 
and snows disintegrate the paper structures, so that in spring it 
is rarely possible to find them, however abundant they may have 
been during the summer previous. 

Wasps are beneficial, as a whole, since they feed largely upon 
other insects and never directly upon crops. They are a nui- 



FiG. 463. 




Nest of Polistes gallicola. 



sance sometimes in the orchard, where they are apt to attack all 
fruits that show the least trace of injury or decay, and they have 
been accused, as, indeed, have the bees as well, of actually punct- 
uring juicy specimens to get at the liquid contained in them. 
Some of the species are undoubtedly useful in pollenizing fruit 
flowers, but there are none of pre-eminent advantage in this di- 
rection. 

The last family in the order contains the bees, and these, as in 
the wasps, may be either social or solitary. The solitary bees 
are those in which male and female only are developed, and their 
habits in nest-building resemble in many cases those of the 
wasps. Thus, we have species that build in the ground, those 
that make cells in the pith of plants, others that are true carpen- 
ters and bore tunnels in solid wood, and, in short, we may find 
bee homes in much the same situation that we find wasp domi- 
ciles. Their cells may be distinguished, however, in all cases by 



A.V ECONOMIC ENTOMOLOGY. 



the fact that they are stored with a mixture of pollen and honey, 
or honey or pollen alone, instead of with insects, and it is this 
habit of collecting pollen that makes the bees so highly useful to 
the farmer, by their incidentally pollenizing the flowers from 
which the material is gathered. There are several interesting 
structural modifications in the bees to facilitate the work of gath- 
ering both pollen and honey, and, incidentally, of accomphshing 
pollination to the best advantage. Thus, the clothing, instead 
of being composed of simple cylindrical processes, is com- 
posed, in large part, at least, of bristly, plumose or twisted 
hair, — that is to say, each hair is furnished with little spurs, 
or long, slender branches, making it resemble a plume under 
the microscope. Or it may be twisted like a screw, or fur- 
nished with a knob at the tip. The result is, that as the insects 
move over the flow^ers, the pollen grains adhere to the vestiture, 
and this also accounts for the fact, probably noticed by every ob- 
servant fruit-grower, that bees frequently bury themselves com- 
pletely in the blossoms, or roll over every part of them. Such 
insects are after pollen, not honey, and by so rolling about the 
pollen grains are brought into contact with and adhere to the 
surface of the insect. Incidentally, also, as soon as the bee flies 
from one flower to another, and repeats this operation, a sufficient 
number of pollen grains from the first flower adhere to the stigma 
of the second and pollenize it ; while in flying from one tree to 
another, cross-poUination is accomplished. The flowers visited 
in this way by a single bee are very numerous. When a honey- 
bee becomes more or less covered with pollen, it cleans itself by 
means of specialized structures on the legs, which enable it to 
literally comb out its entire body covering. The masses of pol- 
len gathered in that way are then rolled into a lump and fastened 
to the upper side of the posterior tibia, where lateral fringes of 
long hair hold it in place and actually form a basket. These 
combing arrangements are situated on the first joint of the hind 
tarsi, which is broadened for that purpose in the social bees, and 
is usually much longer than the other tarsal segments. Some 
bees have pollen baskets not only on the tibia, but on the femur 
and coxa as well, and occasionally the whole posterior portion of 
the thorax and the space between the thorax and abdomen is 
utilized to store the pollen masses. Sometimes the under side of 



Fig. 464, 




A plate of bees. — a, Melissodes bimaculatus ; b, Andrena vicina ; c, Coelioxys 8-dentata: d, 
Halictus ligatus ; e, Synhalomia atriventris ; f, Osmia rustic a ; g, Andrena erigenicE ; h, Melis- 
sodes nigripes ; i, Megachile mendica ; k, Xenoglossa prunina ; I, Tachytes niandibularis ; m, 
Megachile latimanus. All rather more than twice natural size. 




409 



AA^ ECONOMIC ENTOMOLOGY. 



the abdomen contains the pollen-gathering structure, — that is to 
say, the segments of the abdomen are furnished with brushes of 
long, twisted or knobbed hair, and all the pollen gathered by the 



Fig. 468. 




Modifications of the hind legs of different bees.— ^, Apis: a, wax cutter and outer 
view of leg; b, inner aspect of wax cutter and leg; c, compound hairs; d, anterior leg, 
showing antennal scraper. B, Melipojia : f, peculiar group of spines at apex of tibia ; 
g, inner aspect of wax cutters and first joint of tarsus. C, Bombus : h, wax cutter ; 7, 
inner view of same and first joint of tarsus ; all enlarged. 



Fig. 469. 



insect is stored among it, ready for transportation to the nest. 
Pollen, however, forms only one portion of the food of the larva, 
and it must be mixed with honey to form ' ' bee bread' ' of a proper 

composition. This honey is also 
gathered from flowers, and the 
mouth parts are modified to this 
especial end. 

We have two series of bees dis- 
tinguished by the character of the 
mouth parts, — the short-tongued 
and the long-tongued, — both of 
which may be either solitary or 
social. The short-tongued bees 
have the lower lip modified into a bladder-like structure, more 
or less pointed at the tip, and set with regular rows of short hair 
or flattened processes, an ideal tongue for gathering up the liquid 
nectar and bringing it into the mouth. Many of these bees are 
diggers, and build their nests in the ground, usually forming a 
single vertical burrow from which lateral branches diverge into 




Abdomen of Megachile fitted for 
gathering pollen. 



THE INSECT WORLD. 



411 



Fig. 470. 



\\\ \ 



small cells, each containing a supply of food sufficient for a 
single larva. The mother bee constructs a cell, fills it with a 
mixture of pollen and honey, and 
lays an egg in it. Then she closes 
up the chamber, and her work as 
to this particular larv^a is com- 
pleted. When the egg hatches, 
the larva finds a food supply im- 
mediately at hand sufficient to 
bring it to maturity. When it is 
fully grown it changes to a pupa, 
and eventually to an adult, which 
then makes its way from the earth- 
en home into the sunlight. The 
mother bee having completed one 
cell, at once begins the construc- 
tion of another, and thus the 
work is continued until the supply 
of eggs is exhausted. The open 
face of sand- or clay-banks is a 
favorite place for these insects, and 
sometimes they build their nests 
together in great numbers. 

The long-tongued bees are so 
called because the ligula or glossa 
is extended into a flexible ribbon- 
like structure, ringed but not seg- 
mented, set with circles of long 
hair, and frequently tipped with a 
little button-like structure. This 
enables the insect to reach the 
honey in deep flowers like the 
clovers, and in fact there are only 
certain bumble-bees with a tongue 
long enough to reach the nectaries 
of the red clover flowers ; hence 

they are entirely dependent upon these for pollination. Destroy 
the bumble-bees, and no red clover-seed can be obtained. It is a 
suggestive fact that in many localities where ruthless war is waged 





Burrow of Andrena. showing cells in 
order of completion: the first at iz.the 
last at y, in which an egg has just been 
laid. 



412 



A.y ECOXOMIC EXTOMOLOGY. 



against bumble-bees, it is becoming increasingly difficult to obtain 
clo\-er-seed, and for this particular purpose those insects should 
be carefully cherished. They are sometimes a nuisance when in 
the course of mowing or reaping a nest is disturbed, but the 
slight annoyance then caused scarcely warrants the complete de- 
struction of the nest which so uniformly fohows. The farmer 
Avho destroys ever}^ nest of bumble-bees on his land destroys a 
series of insects than which none are more useful to him, particu- 
larly if he raises fruit or has any desire to obtain red clover-seed. 

The long-tongued bees may be either social or solitary, and 
there is no superficial character known to me by which the solitary 
bees can be readily distinguished from the social forms, except by 
the presence of the wax-producing organs in the latter. The 
habits of the bees difter greatly: some are cuckoos, some have been 
supposed to be parasitic, while the majority are undoubtedly 
honest workers and provide decently for their families. ]\Ianv of 
them, as has been already stated, are carpenters, and some of them 
are tailors or upholsterers as well. — that is to say. after ha^-ing 
bored out the wooden tunnel in which the family is to be raised, 
the cells are constructed of leaf fragments. Rose leaves or those 
of other plants of the family Rosacea are frequently noticed with 
circular or semicircular pieces cut from the edges. This is done 
by a bee of this tribe, usually a Megachile. and these little frag- 
ments are used in constructing a somewhat thimble-shaped cell. 
When one of them is completed it is filled with pollen and honey 
and an egg is laid in it ; then another is built on top of it, and so 
on until the burrow is completely filled. As the undermost 
specimen matures first, it bores to the surface through a hole at 
the end, to avoid the necessitv of working its way through all its 
younger relatives above it. The largest of our carpenters is the 
Xylocopa virginica. which is generally mistaken for a Boinbus, 
being fully as large, as robust, and colored yelloAv and black, 
with a metallic blue reflection on the abdomen ; but the head is 
very much broader than in any bumble-bee. and equal to the 
width of the thorax itself The eyes also are larger and white 
or yellowish in color, distinguishing the insect at once from true 
Bombus. This species makes galleries half an inch in diameter 
in the solid wood, and raises a considerable family in the course 
of the year. The partitions between the cells are made in this 



Fig. 471. 




parts are the maxillae. 



THE INSECT WORLD. 



413 



case of little chips of wood cemented together. They are very 
common and sometimes troublesome where they make their 




galleries in the wood of piazzas and out-buildings of country 
houses. Nothing will be gained by giving detailed descriptions 
of these solitary bees, since their general habits are practically 



414 



AN ECONOMIC ENTOMOLOGY. 



alike, and it need only be said that all are useful and none are 
in any true sense of the word injurious. 

The social bees are among the most interesting of all the 
insects, yielding only to the ants in the perfection of their colo- 
nial organization. The domesticated honey-bee. Apis mellijica, 
may be accepted as the type of the highest development in this 
family. Here we have in each hive a queen, or fully developed 
female, who is often, under normal conditions, the mother of 
every individual contained in it. She does not labor, is carefully 
tended by workers who provide for all her wants, and her only 
function is to supply a sufhcient quantity of eggs for the brood- 
cells. The comb made by the hive-bee is so universally known 
that no time need be wasted in describing it ; nor is it important 
to say just how the wax is produced, save to state that it is 
excreted by special glands on the under side of the abdomen of 
the workers in plate-like masses. These are gathered together, 
kneaded by the jaws, and placed in position on the comb. These 
waxen cells are used either as cradles for the young or for storing 
the honey against such time as no food can be obtained ; for, 
unlike the bees previously spoken of, the whole colony lives 
through the winter, and requires a certain amount of food to 
maintain it until work can be resumed the spring following. Of 
these storing habits man has made use ; but there are a number 
of wild species belonging to other genera than Apis that have 
similar tendencies. The life in a hive proceeds something as 
follows : the workers, who are the real rulers, determine about 
how many young should be raised during the season, and build / 
the proper number of brood-cells, making three distinct sizes. 
The smaller are intended for workers, which here, as elsewhere 
in the Hymenoptera, are simply undeveloped females ; the 
larger are to contain males or drones ; while a very few, irregular, 
somewhat flask-shaped cells are plastered at the sides of the 
combs, and are intended for new queens or perfect females. The 
queen lays an egg in each of the brood-cells, and never makes a 
mistake in its character. She lays drone eggs in the drone cells, 
and drones only are produced from them. In the worker cells 
workers only are matured, while in the queen cells fully developed 
females are raised. It is interesting to note that the insects have 
the matter of sex under perfect control, and it is believed that 



THE INSECT WORLD. 



415 



the eggs producing drones are not fertilized : this matter being 
under direct volition of the female. The larvae are carefully fed 
by the workers, and each variety receives a different kind of 
' ' bread, ' ' especially prepared for it. The workers are fed on 
what seems to be best adapted for them ; the drones receive 
another kind ; while the future queens live on a specially prepared 
product, or " royal food," supposed to be much richer in nitroge- 
nous materials. When the larvae are full-grown, the cells are 
capped and the pupae form in?ide of them. In due time the 
adults issue, either drones or workers. In the former case they 
idle about, doing nothing, except to find food for themselves. In 
the latter case they at once assume their full share of the duties 
of the hive, gathering honey or pollen, or attending to whatever 
else is to be done. Of course, by this continuous increase the 
hive soon becomes overcrowded, and then the question arises, Is 
the colony in condition to stand a swarm ? If the store combs 
are tolerably well supplied, and everything is running smoothly, 
the question is decided in the affirmative, and arrangements are 
made to have a portion of the inhabitants leave it. Meanwhile 
the queen larvae have continued to develop, and are now ready 
to assume the adult form. When this period arrives, the ruler 
of the hive becomes uneasy, and does her best to get at the 
queen cells to kill her maturing rivals. If the workers have 
decided that they need a swarm, she is kept from doing mischief 
and they simply block her way. When the new females have 
issued, every effort is made to prevent a meeting between the 
young and old, or even between the young queens, if there is 
more than one. With the new queen or queens fully developed, 
and a larger number of workers than can be readily accommo- 
dated, the members of the hive become uneasy, cease w^ork, and, 
from the noise, appear to be holding a caucus, which finally 
results in a considerable proportion leaving the hi\-e under the 
leadership of either the old or one of the new queens. This is a 
" swarm," and it flies a longer or shorter distance before it settles 
in a solid mass, usually surrounding the queen. If the swarm 
is not hived at once, the bees sooner or later find a hollow tree 
or other cavity, where they start a colony ; but if the insects are 
under the care of a proper keeper, the indications are noted, and 
when the swarm leaves the hive it is induced to alight near by, 



4i6 



AN ECONOMIC ENTOMOLOGY. 



either through a jet or spray of water directed upon it, or by 
beating tin pans or making some other noise. When the swarm 
has settled, the bees can be shaken into a receptacle, and if the 
queen is contained in the mass, as she usually is, they make 
themselves at home readily in any hive to which they may be 
transferred, especially if it contains a small supply of food or a 
piece of comb, full or empty. Work is then started at once, and 
the colony is soon in full swing. From a sound colony there may 
be several swarms in the course of a season ; but if times have been 
bad and the bees have not increased sufficiently to warrant it, 
there is no swarming, and nothing is placed in the way of the old 
queen to prevent her from killing her immature rivals, unless, 
indeed, the bees decide that she is worn out and incapable of 
supplying a sufficient quantity of eggs, in which case they permit 
one or more young queens to come to maturity and let them 
fight it out. The victress remains queen of the hive, and if it is 
the young female, the inhabitants transfer their allegiance to her 
without question, and serve her as faithfully as they did their 
original ruler. If by any chance the bees lose their queen, and 
have no royal larvae, they take worker eggs or very young 
larvae, and by proper care and feeding make queens of them : 
royalty in this case being a mere matter of diet. 

As to the practical part of bee-keeping, and the details neces- 
sary, there are many books especially written to give that infor- 
mation, and it forms no part of the purpose of the present treatise. 
The object here has been to give merely a sufficient insight into 
the working of the hive to indicate the use that is made of the 
pollen and its importance in the economy of bee life. It is the 
necessity of having food for the larvae that keeps the insects 
constantly at work and makes them so effective as pollenizers. 
Visiting, as they must do, a great number of flowers to obtain 
sufficient pollen for a load, they call at many trees, often far 
apart and of different varieties, securing the cross-pollination so 
necessary to many plants. They usually visit one kind of flower 
only, and I have tested several specimens by microscopic investi- 
gation, finding always one form of pollen only. 

Bumble-bees have been already mentioned, and resemble in 
their economy somewhat the hive-bee, save that here, as in the 
wasps, the colony, excepting only the fully developed females, 



Fig, 473. 




Our common bumble-bees. — a, Xylocopa virgmica ; b, Bombus fervidus ; c, B. consimilis ; d, B. 
virginicus ; e, B. americanorum (queen) ; f, B. fervidus ; g, B. americanorum (worker), to show 
pollen mass on hind tibia; h, B. vagans ; i, Apathus elatus. All somewhat more than natural 
size. 



I 



THE INSECT WORLD. 



417 



dies each year. We see early in the spring, when the fruit- 
trees are in bloom, many specimens droning about on the 
flowers, but often also along road-sides, especially where there is 
a declivity; or in fields where there are a few rocks, or where 
there are holes in the ground. There we often notice an indi- 
vidual buzzing over one spot for several minutes at a time, 
apparently subjecting it to the closest kind of examination. This 
is indeed what the insect is doing : she is seeking a place to 
start a home. This she finds in an abandoned mouse-hole, or 
other cavity in the ground, and here begins her nest, lining it 
with moss, with fragments of leaves or grass, or with whatever 
may be most convenient. Then she gathers a mass of pollen, 
upon which a number of eggs are laid. No comb is built ; but the 
larvae, when they hatch, burrow into the pollen mass, to which the 
mother adds constantly as necessity requires. When full-grown 
each forms a smooth cavity, which it lines with a silken cocoon 
and changes to a pupa. The cocoon is strengthened from the 
outside by the mother, with wax, and in due time we have a little 
brood of worker " bumbles" resembling their parent in all except 
size and the incomplete sexual development. Not until after mid- 
summer does the queen, reinforced by the workers which she has 
raised, lay eggs that produce males and females, and these are fed 
upon food gathered by the workers. The old female dies when the 
new brood of sexually complete individuals has hatched. The 
latter mate, and the workers and males also die on the approach of 
cold weather, leaving only the now impregnated females to survive. 

Taken altogether, the order Hymenoptera contains insects that 
are decidedly beneficial to the farmer. The first series only, to 
which the "saw-flies" and the "borers" belong, are injurious, 
and these may always be recognized by the fact that the abdomen 
joins the thorax by its whole width, instead of being fastened 
simply by a stalk or petiole. Of course, the ants are sometimes 
troublesome and indirectly injurious, but, as a whole, the species 
are so overwhelmingly beneficial that the order deserv^es to be 
encouraged in every way possible. Bees, wasps, and hornets 
are particularly desirable inhabitants of a locality, and in a quiet 
way do much to destroy injurious insects, — as much, perhaps, as 
the parasites which also belong to the order ; while the bees of all 
kinds are simply indispensable to the fruit-grower as pollenizers. 

27 



PART III. 

INSECTICIDES, PREVENTIVES, AND 
MACHINERY. 



CHAPTER I. 

PREDACEOUS INSECTS, PARASITES, AND FUNGOUS DISEASES. 

It has appeared throughout this book that, while we have a 
great many insects that are feeders upon vegetation, there are 
also a great number that are predaceous upon the herbivorous 
forms, and yet many others that are parasites, living upon or 
within others of the same class. It is a tempting proposition 
that we may, perhaps, be able to array the forces of nature 
against each other ; that we may keep predaceous forms, and set 
them free at the proper season to feed upon those injurious to 
farm crops. I say it is a tempting proposition, and it looks 
feasible, but that it should be successful involves a great deal 
more than is apparent at first glance. In the course of the ages 
through which this world has existed there has been gradually 
established, by the influence of surroundings, a certain ratio be- 
tween all existing life, vegetable and animal. There is a struggle 
among the plants themselves as to which shall keep the ground, 
and upon the plants feed animals, including insects, which form 
a factor in determining the relative abundance of the diflerent 
species. With the development of the plants their enemies also 
have developed, and always in proportion to the amount of injury 
that the plant can stand. That this must be so is evidenced by 
the fact that the plants exist at all. One of nature's ways of pre- 
venting the plant-feeding insects — for we will confine our re- 
marks to insects from this point on — from obtaining control of 
and exterminating the plants is to provide enemies of various 
418 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 419 

kinds for them. These enemies in turn must be checked, that 
they may not exterminate the species they themselves feed upon. 
Thus there has been estabhshed, gradually and naturally, an 
elaborate system of checks and counterchecks, by means of 
which a certain proportion is maintained year in and year out 
between predaceous, parasitic, and plant-feeding insects. Under 
perfectly natural conditions this ratio does not change much from 
year to year, and there is no preference on the part of nature for 
one class as against any other. Any interference with this estab- 
lished course is almost certain to be disadvantageous in some 
directions, and man, in his dealings with natural conditions, has 
persistently created for himself a series of troubles arising from 
his own acts. By planting large areas of one crop, he has fa- 
vored the increase of the insects feeding upon that crop. By cul- 
tivating the land, keeping it cleared of rubbish, stones, sticks, 
and the like, he has destroyed the shelter needed by predaceous 
insects, and the result is that he has in two ways given those in- 
sects, which he now calls injurious, an advantage. The conse- 
quences, of course, are against him ; and so long as these condi- 
tions continue, favoring one class at the expense of another, man 
must suffer, unless he himself fulfils the functions previously as- 
signed to the predaceous forms. True parasites have not been 
so much influenced by his actions, and the species, perhaps, 
suffer as much from them as they ever did ; but the natural 
checks in operation against the parasites also continue, and 
while, perhaps, they have increased somewhat in number, they 
have not been able to make up for the loss of the predaceous in- 
sects. Furthermore, the feeders upon vegetation suffered also 
from the attacks of insectivorous animals, like toads, frogs, and 
snakes among the reptiles, and many small animals and birds, 
which now also find life insupportable among the artificial condi- 
tions. The result is that there has been an actual increase in the 
number of specimens of injurious insects, and their parasites bear 
somewhat less than their original ratio to them,- — that is, each 
year a certain proportion or percentage of a brood is destroyed 
by its parasites, and this percentage it is beyond our present 
power to change to our advantage. In other words, the farmer 
cannot, except in isolated instances, count upon parasites or 
natural enemies of any kind to keep down injurious insects. 



420 



AN ECONOMIC ENTOMOLOGY. 



Even though in each year a certain species may be, in the long 
run, controlled by its parasite, this does not necessarily help the 
farmer. Let us take, for instance, the cut-worms that are so 
abundant each year. If we gather from an infested field two or 
three hundred specimens, we find that anywhere from fifty to 
seventy-five per cent, of them are parasitized. This looks like a 
huge destruction ; but when we consider that the parasites do 
not, as a rule, affect the larvae until they have done all their 
feeding, what benefit has the farmer derived ? What difference 
does it make whether the cut- worm that destroys his plants is 
parasitized or not ? At the end of the season we may note that 
twenty-five per cent, only of the cut-worms develop into moths : 
half of those may be males, and the remainder are females which 
will each lay anywhere from three to five hundred and some- 
times more than one thousand eggs ; amply sufficient to pro- 
duce in the next brood fully as many caterpillars as existed in 
the beginning ! Let us further take the case of the cranberry 
Teras as an illustration. The first brood, early in the season, 
has scarcely any parasites ; the second brood, in mid-summer, 
is parasitized to the extent of nearly fifty per cent. ; while from 
the third brood, in the fall, we get fully seventy-five per cent, 
of parasites to twenty-five per cent, of moths. Yet, notwith- 
standing this enormous increase of the parasites in the course 
of the season, some combination of circumstances destroys so 
many of them during the winter that in the spring following 
the first brood is again almost free from attack ; and thus it 
goes, year after year. The action of the parasite is only to keep 
its host within a certain fairly well defined limit, and if that 
limit is at a point where the host becomes injurious to the farmer, 
he must himself take a hand in its destruction to derive any 
benefit. I do not mean, in anything I say here, to lessen the 
claims of parasitic and predaceous insects to our consideration. 
They have an extremely important function in nature, and with- 
out them there would be no possibility of an existing vegetation. 
But, on the other hand, it is just as certain that unless there was 
some check imposed upon the multiplication of parasites, etc., 
they would in a short time destroy the insects that they feed 
upon, and the destruction of their host would, logically, carry 
with it their own destruction. Nature never works in that way : 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 421 



her effort is always to give all her creatures an equal chance to 
exist. 

Man has further disturbed the natural conditions by introducing 
into new countries insects that have become adapted to the sur- 
roundings in others. Sometimes an insect so introduced does 
not find the new circumstances to its liking ; but, on the other 
hand, it may find them very much better than those under which 
it was originally developed. In such cases we get a multiplica- 
tion out of all proportion to the normal habit of the species, and 
there may be such a thing as the destruction of the plants that 
they feed upon. Let us take, for instance, the elm-leaf beetle, 
introduced into this country many years ago, and apparently 
without natural enemies suitable for its control. The circum- 
stances which it finds here are so much to its liking that, if 
allowed to increase unchecked by the efforts of man, it may in 
the course of time destroy all the European elms in the regions 
infested by it ! 

The whole object is to show that, since man has introduced 
artificial conditions, he must bear the burden of the change 
caused by them ; and if this means that there are certain injurious 
insects feeding upon the plants he wishes to grow for his own 
benefit, he must replace by his own efforts those natural checks 
which he has removed by the artificial conditions introduced. 
Those efforts on his part consist in the adoption of measures to 
prevent increase, or to destroy the injurious insects by means 
of poisons or otherwise, and this subject will be considered in 
another chapter. 

A fascinating theory in connection with this subject is the pos- 
sibility of importing parasites or predaceous forms from other 
countries for the destruction of pests here. This leaves out of 
consideration the fact that it would require a readjustment of 
matters to induce foreign parasites to feed upon American insects, 
and it has never been proved that such a thing is possible within 
a reasonable period of time. The case of the Australian Vedalia, 
imported to prey upon the fluted scale, Icerya pujxhasi, is fre- 
quently cited as an example of what can be done, but always 
without considering the fact that we had an imported insect to 
deal with in the first place, which increased abnormally in our 
country because of the fact that its enemies were not brought 



422 



AN ECONOMIC ENTOMOLOGY. 



in with it. When this AustraUan insect enemy was introduced, 
it found nothing that it recognized except the Icerya, and, in 
consequence, devoted itself entirely to that species, totally sup- 
pressing it in a short time. All that was done here was to re- 
store the balance of nature, because the scale insect is a tolerably 
rare species in Australia, owing to the number of its enemies. 
Nothing can be argued from this case as to the possibility of in- 
troducing foreign species to control strictly American pests with 
which they are not acquainted. An effort was made in this 
direction in Virginia, the object being to import European enemies 
of bark-borers to check the invasion which seemed to threaten 
the forests of that State. The utmost that can be said for the 
experiment is that the imported insects have not quite died out, 
and that occasionally one is seen out of many hundreds brought 
in. But, on the other hand, the invasion which they were im- 
ported to check has been disposed of by nature herself, an 
unusually severe winter destroying the pests so completely that, 
instead of being abnormally abundant, they have become almost 
rarities. We can frequently do good where we have imported 
insects, or insects occurring also in other countries, by finding 
and introducing their parasites ; but it seems rather an Utopian 
scheme to train predaceous insects of other countries to feed upon 
our native species with which they are not acquainted. 

The subject of fungous or contagious diseases of insects is an 
interesting one, but which must be dismissed here with a brief 
reference only. We know that insects often suffer from disease, 
and that epidemics sometimes occur among them, destroying 
myriads. Some of these diseases have been studied, and elab- 
orate attempts have been made, chiefly in Kansas and Illinois, 
to make use of them practically. The chinch-bug has been the 
insect most experimented upon ; and while it has been demon- 
strated that it is possible to cultivate the disease and to infect pre- 
viously healthy bugs with it, it has also developed that the 
disease demands certain definite conditions of climate and 
atmosphere for its own propagation. Thus, dry, warm weather 
is unfavorable for the growth of the disease, while it favors the 
multiplication of the bugs ; but moist or wet weather, which re- 
tards development in the bugs, favors the disease. Until we can 
control climatic conditions, or otherwise secure the intelligent 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 423 



co-operation of the weather, our results are likely to be uncertain. 
Nevertheless, there may be great possibiHties in this direction, 
and in the minute organisms requiring a powerful microscope to 
make them even visible we may yet find our most effective help 
in checking destruction by insects. 



CHAPTER II. 

FARM PRACTICE TO PREVENT INSECT ATTACK. 

Throughout this work reference has been frequently made 
to methods of ordinary farm practice for preventing insect attack. 
It is desirable to look a little closely into this subject, and to 
detail somewhat the methods that may be resorted to with good 
effect. Prevention is always better than cure, and very frequently 
serious injury may be averted by doing ordinary farm work at 
just the right time, or in exercising care in the selection of fer- 
tilizers or in the rotation of crops. 

Far above everything else is cleanliness on the farm, and this 
term is to be construed as strictly as possible. Cleanliness means 
clean culture ; the destruction of weeds ; the removal of crop 
remnants as soon as the crop is done ; picking up and destroy- 
ing dropped fruit in orchards ; removing, burning up, or other- 
wise destroying all rubbish that cumbers the ground in winter ; 
keeping buildings painted or whitewashed in good shape. Allow 
no rubbish, weeds, or shrubbery to grow among the fences, and 
in all other respects leave the farm as nearly bare as possible 
of everything save what strictly belongs there. The object of all 
this is to do away with possible hiding-places for insects during 
the winter, and to prevent their reaching maturity during the 
summer. A large proportion of insects live through the winter 
in the adult stage, or in the partly grown condition, and a great 
many of them hide under rubbish. Sometimes they get just a 
short distance below the surface of the ground among the roots ; 
sometimes they crawl into crevices of fences, of logs, or of boards, 
— wherever, in fact, there is the least opening for them to get 



424 



AN ECONOMIC ENTOMOLOGY. 



into. A tree with rough bark, covered with moss, hchens or 
other unnecessary growth, often harbors hundreds of specimens, 
and one object of the farmer should be to destroy all hiding- 
places that may be of service to the insects for winter-quarters. 
Therefore, if possible, all fences should be whitewashed, as well 
as all out-buildings. Insects do not like lime, and where a dozen 
specimens may be found on a plain board fence, scarcely one 
will venture on one that is limed. This kind of campaign is 
especially effective against certain forms of plant-bugs, a large 
proportion of which live through the winter in the half-grown or 
adult condition. Offer them a bare soil wherever that is agricul- 
turally feasible, and at all events never give them the opportunity 
of hibernating in a weedy field — one that has been allowed to 
grow up after harvest with the idea that it is to be turned under 
in the spring. Such fields are veritable nurseries for insect pests. 

It frequently happens that a farmer is through with a crop 
before the plants stop growing, and occasionally they remain in 
the field weeks after they have ceased to be of any practical use. 
During all this time the insects peculiar to that crop are multi- 
plying, coming to maturity undisturbed, and providing for their 
increase during the ensuing year. For instance, with cabbages : 
if, after the heads are taken out, the butts and outer leaves are left 
in the ground, the cabbage-lice will there increase and prepare 
for the winter. If the butts are taken out and fed up, or destroyed 
in any other satisfactory manner, it will put an immediate stop 
to their development ; and if the practice is continued systemati- 
cally, and cruciferous weeds are also kept down on the farm, 
cabbage-lice will soon become so reduced in number as to be 
practically harmless. So, from melon vines only a portion of 
the crop is often gathered, and they are then left to grow and 
decay naturally upon the ground. The vines may be infested by 
borers, or they may harbor squash-bugs, or melon-lice, or a 
number of other pests. By removing and destroying as soon as 
there is no further use for them, a period is at once put to the 
increase of these insects. They will be compelled to look else- 
where for food or will starve to death. 

In corn-fields, leaving the roots and stumps in the ground 
throughout the winter offers a premium for the increase of insects 
that depredate upon this crop. Such pests as corn-worms" 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 425 



can be easily kept in check by fall ploughing and burning the 
butts and roots, and a good effect will also be produced as against 
the corn-root-louse and similar pests. Instances might easily be 
multiplied without adding to the force of the suggestion that the 
ground should be kept as free as possible from all growth that 
might afford lodgement or shelter for insects. 

Another important operation which can be made use of is 
ploughing at the proper time, and, among other things, fall 
ploughing, whenever possible, is to be recommended, especially 
of sod land. Many different kinds of insects live in sod, among 
them cut-worms and wire-worms, both well-known and important 
pests. A great deal can be done in the direction of destroying 
these creatures by ploughing the land late in fall. Under the 
proper headings will be found the reasons why such an operation 
proves beneficial in special cases ; but in general we can say that, 
by disturbing the land after the insects have prepared for their 
winter rest, they are exposed to their natural enemies when more 
helpless than usual. A great many are then in the pupa state, 
absolutely unable to help themselves, and breaking their cells at 
that time means death to them. A very large percentage of 
reduction in the number of injurious insects can be effected by 
this practice alone. I am aware that fall ploughing is inadvisable 
on some kinds of land, but it is directly beneficial on others. It 
is a measure that must be used with judgment, and each farmer 
should know enough about his own land to decide whether or not 
fall ploughing is advisable. I distinctly recommend it wherever 
it is possible. As a rule, where the ground is to remain bare, 
the ploughing should be done as late in the season as possible, 
that the insects may not be able to re-establish themselves ; for 
instance, when the corn-root-louse is the object of the attack, 
early ploughing allows the ants that shelter them to construct 
new galleries and gather in their belongings to safe shelter, while 
very late ploughing makes it impossible for the ants to work, so 
that they and the lice both perish : the latter almost certainly. 
The date of ploughing, other than in fall, is sometimes important ; 
thus, against the root web-worms in fields after grass, if the sod 
is turned very early, before the moths have appeared and laid 
their eggs, the crop remains free. If delayed until the sod has 
become stocked v\-ith eggs, the corn is almost certain to suffer. 



426 



AN ECONOMIC ENTOMOLOGY. 



Sometimes, where land cannot safely be left bare during the 
winter, it may be ploughed earlier, and some catch crop, simply 
to cover the surface, can be put in, and it matters very little what 
this is. It may be crimson clover, rye, wheat, — anything, in 
fact, to get a covering, provided it is something radically different 
from what was on the ground before the ploughing was done. 
Corn-fields should be treated in this way after the crop has been 
harvested, if late ploughing is undesirable, for it is always a mis- 
take to leave them unturned until the spring following. It is 
a good plan, just as soon as one crop is off, to put in some- 
thing else, which, as already suggested, should be quite different 
in general character ; and this brings up the question of rotation. 
It is impossible to make any generally applicable statements on 
this subject. No two regions of our country are entirely alike in 
their practice, in the crops raised, or in the rotation adopted ; 
but so far as possible a rotation should be selected which will 
keep the ground covered all the time, the crops that follow each 
other being unlike in their natural family, — that is, grass should 
not follow wheat or rye, if it can be avoided ; nor should potatoes 
be followed by egg-plants or tomatoes ; or cabbages by mus- 
tard or radishes ; but in all instances crops as diverse as may be 
should follow each other, and as rapidly as possible. Where 
wire-worms are the chief sinners, crimson clover may sometimes 
be usefully employed. Plant this in fall, and in spring it will be 
in excellent condition to attract the adults to lay eggs. Turn it 
under late in May or early in June, after cutting for hay or as a 
green manure, and plant any suitable crop. The very young 
larvae will be incapable of doing injury, and will fail to maintain 
themselves under the new conditions. It must be remembered, 
however, that this practice will favor cut-worm increase, and 
measures must be held in readiness for these when the planted 
crop makes its appearance. 

Another good plan is to have a considerable number of 
chickens, and to train them to follow the plough. This can be 
very easily done, and after a few are once trained, they will in 
turn teach the entire flock, while the young learn readily from 
the older. Chickens following a plough will pick up almost 
every insect that is turned up, be it in the larval, pupal, or adult 
condition, and they are especially effective in fields infested by 



IXSEC TIC IDES, PREVEXTIVES, AXD MACHIXERY. 427 



white grubs. Badly infested fields may even be ploughed more 
than once, and in different directions, just to give the chickens 
an opportunity of picking up the insects. I have seen flocks so 
well trained that whenever the plough harness was put upon the 
horse they gathered together, waiting until he was taken to the 
field. 

Turkeys are exceedingly useful where grasshoppers are to be 
dealt with, because they are especially fond of these insects ; and 
for the same purpose Guinea-fowls are also advisable. Here 
again the practical farmer will find, with a little observation, just 
about the range of usefulness of the various fowls, and will be 
able to adapt his cultivation somewhat to their peculiarities. 

In the matter of the fertilizers to be used we have also an oppor- 
tunity for careful selection. W^e may say generally, that manure 
and all vegetable matter in a decaying state favors the develop- 
ment of insects. It affords both food and lodgement to many 
species, and when it is put on in the fall or winter in a coarse 
condition, it is a direct benefit to insects that hibernate, even 
when ploughed under. On the other hand, the mineral fertil- 
izers, especially those containing a considerable percentage of 
salt, are unfavorable to insects of all descriptions, and to some 
they are deadly. Experience has shown that plant-lice are sus- 
ceptible to the action af the salty fertihzers, and that cut-worms 
and wire-worms are affected by them to a considerable extent. 
Among corn insects, injury from the root web-worms may be 
entirely avoided by using the mineral fertilizers instead of barn- 
yard manure, if fall or very early spring ploughing is not feasible. 
So the time of application is important, as is the amount to be 
applied. For instance, in land infested by wire-worms and to be 
put into corn, the best time for the application is just after it has 
been prepared and after the seed has been planted. Then all 
the potash should be put on, in the form of kainit, in one appli- 
cation, while as much as is desirable of the nitrogen should be 
put on in the form of nitrate of soda. In this way the soil 
becomes impregnated with a rather concentrated salty mixture 
which is fatal to many of the insects. The same amount of fer- 
tilizer distributed in several applications, or put on the ground in 
fall, or when vegetation covers it, would be entirely ineffective. 
Mineral fertilizers are advisable wherever their use is otherwise 



428 



AJV ECONOMIC ENTOMOLOGY. 



profitable, and are always to be preferred to decomposing vege- 
table matter, from the insect stand-point. The details of the 
applications to be made are found where the insects themselves 
are treated. Where barn-yard manure must be used, it is always 
a good plan to mix it wath air-slacked lime, land plaster, or kainit, 
and this can be done as fast as it is made in the stable. It will 
add to its value, wdll hold the ammonia, and will make the mixture 
an undesirable one for insects to live in. 

Grass land may be kept tolerably free from undesirable pests 
infesting the roots by using as fertilizer a mixture of one hun- 
dred bushels of lime and one ton of kainit slaked together. This 
may be applied in the spring, and will act as a stimulant as well 
as destroy many of the insects inhabiting the soil. 

There are yet other ways in which we can head off* insects ; for 
instance, in the selection of the time of planting. It happens 
frequently that insects make their appearance at a very definite 
time, and in the ordinary course of nature have only a few days 
within which they must lay their eggs and provide for the con- 
tinuance of their kind. If they do not find the cultivated food- 
plant, they are compelled to make use of some substitute wild 
plant, on which they do not thrive as well ; or they may not be 
able to oviposit at all, and a large proportion will p^ish without 
being able to reproduce their kind. 

When the life history of a seriously injurious insect is known, 
it will often pay to adapt our farm practice so as to prevent injury. 
For instance, experience has proved that the Hessian-fly appears, 
ready to lay eggs for a late fall brood, during the early days of 
September. By delaying planting until after the middle of that 
month, or even later where the latitude makes this feasible, the 
insects are compelled to lay their eggs in grasses other than 
wheat, or in the volunteer grain that they find in fields or along 
the roads. 

Cranberry growers take advantage of their knowledge of the 
life history of the Teras infesting that crop by keeping the bogs 
covered with water until after the middle of May, thus compelling 
the moths to lay their eggs on other plants belonging to the same 
natural family. 

In a similar way we can sometimes induce the insects to ovi- 
posit in a trap crop planted especially to attract them and pro- 



INSECTICIDES, PREVEXTIVES, AND MACHINERY. 429 

tect the staple. An example of this is the practice of certain 
squash growers, who plant early summer squashes to attract the 
borers, and Hubbards and marrowfats rather late, so as to be 
unattractive to the moths as compared with the vigorous early 
plants. The summer varieties may be taken out and destroyed, 
with all their contents of borers, after an early crop has been 
picked from them, and this will leave the later varieties free, 
while it also accomplishes the destruction of an entire brood of 
larva. So it has been found practicable in the South to protect 
cabbages from the attacks of the harlequin cabbage-bug by 
planting an early trap crop of mustard, to which the insects are 
attracted, and from which they can be gathered by hand or 
destroyed by spraying with pure kerosene. 

An instance of the use of methods of cultivation we find in the 
practice of blackberry growers, who, to prevent injury from the 
red-necked cane-borer, cut off during the latter part of June all 
the shoots then above ground, and either gather and destroy, or 
merely allow them to wilt and die. The beetles have all disap- 
peared at this time and all their eggs are in these shoots. The 
new canes that come up after this trimming become sufficiently 
mature and are in sufficient number to make next year's crop, 
while they are free from any possible beetle attack. 

There are many other ways in which farm practice may prevent 
injury from insects, and to the intelligent farmer these methods 
will commend themselves much more than the indiscriminate use 
of insecticides after damage has been caused. The prevention of 
attack is always better than the destruction of the insects after 
injury has been accomplished, and some of these methods have 
the advantage of effecting a permanent reduction of the injurious 
species. Further details are hardly in place here, but what has 
been said will explain the reason for many of the recommenda- 
tions made in the body of the work. 



430 AN ECONOMIC ENTOMOLOGY, 



CHAPTER III. 

PREVENTIVES. 

There are many insects seriously injurious to trees that are 
difficult to reach with insecticides of any kind, and are with diffi- 
culty destroyed in any way, and first among these are borers, 
whatever the order to which they belong. It has been already 
indicated under various headings what measures are available for 
preventing and curing injury, but perhaps a grouping of what 
may be termed preventive measures will be of some use. It is 
the fruit grower that suffers most from boring insects, and while 
small fruits are often attacked, the most serious and permanent 
injury is done to trees. Peach-trees are girdled at ,or near the 
surface of the ground by a Lepidopterous borer ; apple, pear, 
quince, and similar trees are attacked on almost all parts of the 
trunk, yet preferably near the base, by Coleopterous borers, and 
almost all our fruit-trees are subject to the attack of bark-beetles. 
Many of our shade-trees also suffer from boring insects of various 
descriptions. It is often easier to keep these borers out than it 
is to destroy them after they once get in, and to do that we must 
resort to mechanical measures. The simplest as well as most 
effective method is the use of a wire mosquito netting on apple, 
quince, and similar trees. The parents of both the round and 
flat-headed borers infesting these trees are quite large insects, un- 
able to oviposit or lay their eggs through the meshes of an ordi- 
nary mosquito netting, provided it be kept at least half an inch 
from the bark at all points. In this way apple-orchards and those 
subject to the same kind of injury may be effectively protected, 
and trees once netted will need little attention, except an occasional 
retying, for several years. The wire netting should, of course, 
be thoroughly painted in the first place, and should have suffi- 
cient lap, when cut, to allow of considerable growth of the tree. 
The top must be closed by being tied tightly to the trunk, or the 
interval between the trunk and netting must be filled with cot- 
ton or some similar material, that the insects cannot crawl under 
it. In like manner the ground must be hilled around the wiring 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 431 



at the base, to prevent the entrance of insects at that point. If 
it should happen that trees are already infested, the beetles that 
come from the trunk will be unable to get away and should be 
killed through the netting. 

Wrapping with newspapers or tarred paper is another satis- 
factory and tolerably effective measure. Newspapers will last a 
season without being renewed ; tarred paper may last longer, but 
will need retying. The tar adds nothing to the effectiveness of 
the paper, but serves to protect it and make it more lasting. The 
covering must be complete, so that the insects cannot get be- 
neath it. Here also any insects already in the trunk of the tree 
will be kept in and perish. This is applicable to all insects, what- 
ever the size, and will prove effective in proportion to the care 
used in fastening the paper in place. 

Instead of these materials, the German raupenleim or the 
American dendrolene may be appHed. Both are crude petro- 
leum products, and are in the nature of an impure vaseline, more 
or less greasy, smooth, of a butter-like consistency at ordinary 
temperatures, and absolutely resisting wash by rains. Applied 
three-sixteenths of an inch thick or more to the surface of the tree 
to be protected, they will last an entire season without] renewal. 
The raupenleim hardens, after a time, into a crust, while the 
dendrolene tends rather to become absorbed. No insect will 
rest upon these materials long enough to lay an egg, and no larva 
can bore through them to reach the trunk ; hence one thorough 
application is an effective protection against borers of all kinds, 
bark-beetles as well as others. As against the smaller species, 
the materials answer to destroy the borers already in the tree by 
preventing them from coming out through the bark. Applied 
around the base of peach-trees, borers may be kept out, and, of 
course, no scale insect can set where they are used. Like all 
other mechanical protections, they are effective in proportion as 
they form a complete covering to the bark, and probably in no 
other way. 

Either raupenleim or dendrolene, particularly the latter, is 
effective in preventing injury by canker-worms or other insects 
that crawl up the trunk to reach the leaves, whether in the moth 
state to oviposit or in the caterpillar state to feed. A broad band 
of dendrolene, put on early in the spring, will absolutely pre- 



432 



AiV ECONOMIC ENTOMOLOGY. 



vent injury by canker-worms, because it hinders the female from 
reaching the branches to lay her eggs. In the same way, trees 
cleared during the winter of the egg masses of the vaporer moth 
or of the sacs of the bag-worm may be kept cleared during the 
year following by a band of these materials. It is said that 
raupenleim, under the influence of cold nights, becomes too 
hard to be effective, but this is not the case with dendrolene. 

A word of caution must be added. Both of these materials 
penetrate to some extent, the dendrolene more than the raupen- 
leim, because it never becomes hard and never dries. On thin- 
barked or very young trees, if it is left on continuously, it will 
check the growth of the bark, kill the outer layer, and may in- 
juriously affect the inner bark or sap-wood. This is especially 
true of peach-trees, and on such the materials should not be 
applied very heavily, and should be washed off after midsum- 
mer with some potash wash. Both raupenleim and dendrolene 
dissolve readily in benzine, turpentine, or kerosene, and they 
combine easily with any caustic ; hence the bark can be cleared 
without very much trouble after the danger season is over. On 
old trees, where the outer layer of bark is no longer active, no 
danger is to be apprehended. Where trees are banded against 
the canker worm or similar insects, the easiest way would be to 
first tack a band of heavy wrapping-paper close to the trunk and 
apply the material to that. It should be smeared over the edges 
of the paper to the bark, so as to prevent any insect from getting 
under it, and when the danger season is over this band can be 
cut away without trouble, leaving only a narrow ring of the 
smear, which could do no harm. Where protection against 
borers only is sought, all injury can be avoided by mixing 
the dendrolene with dry earth or with land plaster, weight for 
weight, which will not reduce its value as a covering, but will 
diminish its penetrating qualities. 

Lime is an exceedingly good preventive, applied in the form 
of whitewash. Fruit-trees that have the trunks whitewashed 
early in spring will be apt to remain measurably free from scale 
attack, and if it is appHed fresh, a great many of the scales already 
upon the trunk will be killed. It is an advisable thing, when 
Bordeaux mixture is applied, to use plenty of Hme, especially 
upon the trunks and branches of the trees, because no scale in- 



IXSECTICIDES, PREVEXTIVES, AND MACHIXERY. 433 



sect can or will set on a lime-covered surface. Of course, lime 
washes away readily, and must be renewed from time to time to be 
thoroughly effective. Keeping it up until midsummer, however, 
is usually sufficient, except against scales that have several broods. 

Under the heading of "preventive measures," keeping the 
trees clean, free from all sorts of abnormal growth and from loose 
bark, may be counted. Winter washing the trunks with a strong 
potash solution is always advisable. This cuts away anything in 
the form of fungus, moss or lichen growths, and leaves the bark 
fresh and glossy for the season following. It also destroys 
many of the insects hibernating upon the trunk in any stage. 

Finally, the most important of all preventive measures is good 
farming. Keep crops of all kinds in the most vigorous possible 
condition, with plenty of readily available plant food, and in 
orchards allow no dead wood of any kind to remain over winter. 
Dead or dying branches should be cut, carted out, and burnt 
before the first warm spell of spring, and dying trees should meet 
the same fate. There will then be nothing to encourage insects 
either to come into the orchard or to remain there if accidentally 
brought in. Good farming, it may again be said, is the very best 
possible preventive of insect injury. 

It is necessary to merely mention that printer's ink, birdlime, 
and perhaps other substances have been recommended for band- 
ing trees, or for the purposes for which raupenleim and den- 
drolene have been recommended. The latter are so much more 
satisfactory and lasting that they should replace all similar sticky 
or protective coatings. 

To prevent climbing cut worms, canker-worms, or similar 
creatures from ascending a tree, a band of cotton batting can be 
satisfactorily used in many cases as follows : Make the band from 
eight to twelve inches wide and long enough to go round the 
trunk and lap two inches. Tie tightly at the bottom of the band, 
smooth side, if any, to the trunk, and then turn down the band 
from the top, like an inverted funnel. This prevents the inner 
- side of the funnel from matting when wet by rains, and under 
ordinary circumstances forms a complete bar to the ascent of 
insects. A band of this kind above a coating of dendrolene, to 
prevent the bark from being eaten, ought to protect even very 
young orchards from climbing cut-worms. 

28 



434 



AN ECONOMIC ENTOMOLOGY. 



CHAPTER IV. 

INSECTICIDES. 

Some of the principles governing the appHcation of insecticides 
have been referred to and stated in previous parts of this work, 
but it is deemed advisable to refer specifically to the different 
kinds of materials, and to mention the range of the most useful 
among those now upon the market. Broadly speaking, we may 
say that insecticides are of two kinds,— those that kill by being 
eaten, or stomach poisons, and those that kill by contact. Some 
substances, such as hellebore and tobacco, belong to both cate- 
gories, — that is to say, they are poisonous when eaten, and, 
when properly applied, also kill by contact. 

Of the stomach poisons, none are in more general use or of 
greater importance than the preparations of arsenic, and of these 
three only need be considered here, — Paris green, or arsenite of 
copper, London purple, or arsenite of lime, and "gypsine," or 
arsenate of lead. All of these have very much the same range 
of usefulness, and may be treated together. In each case the 
active principle is arsenic, and the combination with the other 
material is simply to put it into an insoluble form to prevent 
injury to the plants ; for arsenic is quite as violent a poison to 
plants as it is to animals. In Paris green tlie arsenic is in combi- 
nation with copper, and in many cases we get, besides the in- 
secticide effect, a direct influence upon fungi. An average good 
sample contains about as follows : 

Per Cent. 

Moisture 74 

Arsenious oxide (AsgOa) 68.82 

Copper oxide (CuO) 30.59 

100.15 

A small quantity of the arsenic remains here in a soluble con- 
dition, especially when the weather is warm ; hence we frequently 
find that spraying on a hot day is much more likely to burn the 
foliage than when done on a cool day, or late in the afternoon. 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 435 



This is due entirely to the fact that the water appHed to the leaves 
becomes rapidly warmed up by the sun before evaporating, and 
meanwhile dissolves every particle of soluble arsenic, bringing it 
into direct contact with the vegetable surface upon which it rests. 

In London purple we have a decidedly smaller percentage of 
arsenic, as will be seen by the following analysis : 



More of the arsenic is soluble here, which explains why London 
purple is more apt to burn foliage than Paris green. Both the 
insecticides just mentioned can be made entirely harmless to 
foliage by adding weight for weight of caustic lime when mixing. 
That is to say, in preparing the poison for use, take one pound 
of Paris green or of London purple and one pound of quick- 
lime ; add water enough to slake the lime, and mix thoroughly 
while hot, so as to incorporate lime and poison completely. This 
will fix with the lime every particle of the soluble arsenic con- 
tained in the mixture, and it can then be diluted with water and 
applied at almost any reasonable strength without much danger 
of injury to even the most tender foliage. 

Paris green, containing the greatest percentage of arsenic, will 
go furthest for insecticide purposes, and for most insects will be 
effective when applied in liquid form at the rate of one pound in 
two hundred gallons of water. Used against the plum curculio, 
or against the codling-moth, one pound in one hundred and 
seventy-five gallons is more effective. Used against the potato- 
beetle, one pound in one hundred gallons is most satisfactory. 
Used in a dry condition, the Paris green may be applied without 
any danger of injury, provided the application be made in a very 
fine dust. It can be mixed with plaster of Paris, flour, or air- 
slaked lime, and, practically, one pound of Paris green in one 
hundred pounds of lime or plaster makes a good mixture, effec- 
tive for insects of almost all kinds and harmless to plants. There 



Per Cent. 



Moisture 

Arsenious oxide (AsgOg) .... 

Lime (CaO) 

Iron and alumina (FeaOa-r-AlaOs) 

Sulphuric acid (SO3) 

Dye, by difference 



3-27 
41.44 
24.32 

3-37 
•31 
27.29 



100.00 



436 AA^ ECONOMIC EXTOMOLOGY. 

are some instances when the dry appHcation is to be preferred 
to the spray, as in the cotton-field against the cotton-worm and 
against potato-beetles. The essential points in powder applica- 
tions, where the substance is to be used undiluted, is to have it 
perfectly dry, and to put it on very thinly and evenly. Paris 
green, to have the greatest effect, should be extremely fine ; the 
finer the particles the more effective will be the application and 
the greater the surface covered by an equal amount of poison. 
Where used in water it remains in suspension better in propor- 
tion as the material is in good mechanical shape ; the larger the 
grains the more rapidly they sink to the bottom. In applying 
Paris green it must always be remembered that there is no solu- 
tion, but merely a mechanical mixture ; that the substance is 
heavy and will sink to the bottom unless it be kept constantly 
stirred. 

London purple is a waste product, and its composition is not 
in all cases quite the same, but under ordinary circumstances 
does not vary much from the analysis given. It should always 
be mixed with lime, as already described, before being used. It 
is effective against most insects at the rate of one pound in one 
hundred and eighty gallons of water. Against the plum curculio 
or the codling-moth, one pound in one hundred and fifty gallons 
of water is more effective ; while against the potato-beetle, one 
pound in one hundred gallons is generally satisfactory. London 
purple can also be used dry, but should never be used pure in this 
way, because even a small degree of moisture may have the efiect 
of liberating some of the free arsenic and causing injury. It is 
best combined with air-slaked or dry hydrate of lime, and is 
then both effective and harmless. The material is very much 
finer and lighter than Paris green, and remains in suspension in 
water very much better ; therefore, less stirring is required ; but 
all the other points that have been referred to under Paris green 
apply here equally well. 

Arsenate of lead, or "gypsine," stands on a difierent footing, 
yet acts in the same way. This must be made, as used, of arse- 
nate of soda four ounces and acetate of lead eleven ounces, or 
in that proportion for a larger or smaller quantity. These sub- 
stances dissolve readily, and the quantities given can be mixed 
in one gallon of water for dilution, or can be placed in one 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 437 

hundred gallons ready for use. This combination has the ad- 
vantage of being harmless to foliage, whatever the strength in 
which it is applied. The fifteen ounces of mixed arsenate and 
acetate have been applied to peach-trees in two gallons of water, 
and this — the most dehcate and sensitive of all fruit-foliage — 
was absolutely uninjured. The mixture is less poisonous than 
either Paris green or London purple, containing, as it does, a 
smaller percentage of arsenic in an absolutely insoluble form ; 
but it is also much cheaper, and to obtain the same effects costs 
just about the same, or a trifle less. As a rule, four ounces of 
arsenate of soda and eleven ounces of acetate of lead will suffice 
for one hundred gallons of water, and this mixture will be effec- 
tive against most insects, including the elm-leaf-beetle in all its 
stages, the various w^eb-worms, canker-worms, and the codling- 
moth. Where a rapid effect is necessary, the quantity can be 
doubled. Where a great deal of the mixture is to be used, it 
can be made in a concentrated form, and a proper proportion of 
the stock added to each tank of water as used. Arsenate of 
lead does not dry, but forms an almost pure white, pasty pre- 
cipitate. It remains well in suspension, and needs but little 
stirring. Its great advantage is its harmlessness to plant-life of 
all kinds. It should not cost above eight cents per pound for 
arsenate of soda and fourteen cents per pound for acetate of 
lead, or about thirteen cents per fifteen ounces for the arsenate 
of lead. 

Pure white arsenic has been recommended, and is used with 
satisfaction by some agriculturists. It is certainly the cheapest 
as well as the most active of the poisons of this class. It is effec- 
tive at the rate of one pound in from two hundred and fifty to 
five hundred gallons of water, the latter strength corresponding 
to Paris green at one pound in two hundred gallons, and the 
former to one pound in one hundred gallons. It contains much 
more soluble arsenious acid than either of the other mixtures, and 
will burn foliage severely unless mixed with twice its own weight 
of quick-lime. If that be done, however, an insoluble arsenite 
of lime is obtained which is exceeding effective and can be used 
as safely as any of the other mixtures. 

There is sometimes a Httle difficulty in making a water mixture 
stick to very smooth, or spread over very hairy leaves, and in 



438 



AJV ECONOMIC ENTOMOLOGY. 



such cases the addition of one pound of soap to every forty or 
fifty gallons of water will aid matters considerably. The mixture 
will spread much more completely, and will adhere even to very 
smooth or feathery foliage if a fine spray nozzle is employed. 
One quart of molasses or, better, glucose in every fifty gallons 
of water will also greatly increase the adhesive and lasting quali- 
ties of any mixture employed. 

These arsenical poisons act only through the stomach, and no 
insects are able to resist them entirely, although some bear a 
considerable amount without showing immediate effects. When- 
ever they are available, it will pay to use them to the exclusion 
of other materials. There is no other stomach poison that com- 
pares with them. And here it may be advisable to say a few words 
concerning a great many ' ' harmless' ' insecticides placed upon 
the market. 

As a matter of fact almost all the commercial insecticides other 
than pastes or soaps contain arsenic in some form or shape, and 
this is in most instances the killing agent. It is also quite true 
that under ordinary circumstances the preparations are ' ' harm- 
less" to man, because in so diluted a form. As these poisons 
are used upon plants, the proportion is so small that danger to 
life is not to be anticipated, except as a result of the grossest 
carelessness ; hence, strictly speaking, the mixtures are ' ' harm- 
less," though containing arsenic. The purchaser, however, usu- 
ally pays at least three prices, and, in addition, freight charges 
upon a mass of inert diluting matter. 

There is another way of using the arsenites which should be 
briefly referred to here, — i.e., in a poisoned bran mixture, to 
attract cut-worms and some other insects to a deadly feast. Mix 
one pound of Paris green, or half as much white arsenic, with 
fifty pounds of bran, making the combination as perfect as pos- 
sible ; then add water enough to moisten thoroughly, so that the 
mixture can be ladled out with a spoon without dripping. A 
little sugar or molasses in the water makes the mass rather more 
adhesive and lasting, but apparently no more attractive to the 
insects. How this mixture should be used will be found stated 
in those cases where its employment is indicated. 

Bichloride of mercury, or ''corrosive sublimate," is an ex- 
tremely violent poison, of which some use has been made, but 



IXSECTICIDES, PREVENTIVES, AND MACHINERY. 439 



generally with only small satisfaction. It is a deadly poison 
and effective against insects, but, unfortunately, is just as injurious 
to plants, and the limit of effectiveness as between plants and 
insects is so narrow as to render its use undesirable in most cases. 
It is valuable only in those few instances w^here it is desirable to 
poison a prepared food or bait, and its use is not advised, except 
in special cases where particular directions are given. 

The Bordeaux mixture, though primarily a fungicide, has 
excellent insecticide qualities in certain cases, and, among others, 
it seems to be almost a specific against flea-beetles. This is an 
important feature, and renders its use doubly valuable on pota- 
toes, egg-plants, tomatoes, and other crops susceptible to flea- 
beetle attack. Either Paris green, London purple, or white 
arsenic may be added to the Bordeaux mixture where a com- 
bined insecticide and fungicide is desired, but Paris green is the 
best. London purple only can be added to the ammoniacal 
carbonate of copper, since the ammonia in the fungicide acts as 
a solvent to the arsenic in Paris green. Either of the fungicides 
may be treated as replacing water, in determining the amount of 
the insecticide to be used. 

The formula for the Bordeaux mixture is as follows : 



Sulphate of copper 6 pounds. 

Quick-lime 4 pounds. 

Water 22 gallons. 

Dissolve the copper sulphate in one gallon of hot water, and 
in another vessel slake the lime with a gallon of water ; add the 
milk of lime slowly to the copper solution, stirring constantly, 
and strain through a sieve or coarse gunny sack ; finally, add 
twenty gallons of water, and the mixture is ready for use. This 
gives the standard full-strength mixture, and half strength or 
other proportionate strengths are produced by simply adding 
more water. 

The ammoniacal solution of copper carbonate, or "cupram," 
is made as follows : 

Carbonate of copper 5 ounces. 

Ammonia water (twent>'-six per cent, strength) . 3 quarts. 
Water 30 gallons. 



440 



AN ECONOMIC ENTOMOLOGY. 



Wet up the copper carbonate in a quart of water, add to it the 
ammonia, and when completely dissolved and diluted with the 
water the compound is ready for use. 

Holding a sort of intermediate position between stomach and 
contact poisons are powdered white hellebore and tobacco, both 
of which may be used pure in the form of either a finely ground 
powder or a decoction. Hellebore has a very narrow range of 
effectiveness, and is particularly useful only against saw-fly larvae 
like the ' ' currant-worm. ' ' If used dry, it can be dusted on pure 
or mixed with twice its own weight of land plaster or cheap 
flour, and will kill by being eaten or by coming into contact with 
the insects. If a spray is preferred, it is generally effective within 
its range at the rate of one ounce in two quarts of water, and 
sometimes, in the case of young saw-fly larvae, one ounce in one 
gallon of water will be sufficient. The material should be steeped 
in one pint of boiling hot water, and the cold water added grad- 
ually. The sediment can be sprayed on with the liquid, or it 
can be thrown away and only the extract used. The decoction, 
at the rate of two ounces in one gallon of water, has been highly 
recommended against the cabbage-maggot, but the reports are 
too contradictory to make it advisable to rely upon it for that 
purpose. 

Tobacco has a very much wider range of usefulness ; few in- 
sects care to eat of it, and a plant thoroughly sprayed with a decoc- 
tion is safe from the attacks of flea-beetles and a great variety of 
other insects. It is as effective against the saw-fly larvae as is 
hellebore, and may be applied in much the same way. It may, 
in many instances, be applied at the base of plants to keep off 
borers and root-feeders generally : for instance, against the cab- 
bage-maggot, a handful of tobacco dust at the base of each plant 
will usually serve as a tolerably complete protection. It is as a 
contact poison that it has the greatest advantages, and it may be 
used effectively against plant-lice, either in a dry powder or in 
decoction. If used as a powder, it is very important that it 
should be as finely ground as possible. All contact poisons kill 
through the stigmata, or spiracles. The fine dust makes its way 
through the breathing pores into the trachea, and sets up an irri- 
tation which results in the death of the insect. The coarse par- 
ticles are sifted out by the protective structures with which most 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 441 

insects are supplied, but very fine particles often make their way 
through them. It is important, therefore, if tobacco is to be 
used dry, that it be in as fine a condition as it is possible to ob- 
tain. This applies even where it is used on the surface of the 
ground around cabbage plants. As a decoction its range of 
usefulness is greater. It is fatal to a large number of caterpillars 
of the smaller moths, both as a contact and as a stomach poison, 
and cranberry growers in Massachusetts use great quantities of it, 
at the rate of one pound to one gallon of water, against ' ' vine- 
worms" and "fire-worms." Stems and other refuse are just as 
good as leaf tobacco for this purpose, and the usual method is to 
boil down the coarsely chopped stems until a deep brown extract 
is obtained. This is also effective against plant-lice. Ground 
tobacco may be applied on the surface around trees infested with 
root-lice, and the result will be beneficial, especially in light soil. 
As against the peach-root lice, tobacco has been employed by 
first trenching around the base of a moderately large tree at a 
distance of two feet from the trunk, and applying the tobacco 
dust in the trench. To obtain the greatest effect there should be 
an early application of water, either in the form of rain or arti- 
ficially, to dissolve the nicotine and carry it into direct contact 
with the root-feeding lice. As tobacco is also a fertilizer, quite 
rich in potash, the benefit to the plants is doubled where the 
material is applied to the soil. As a stomach poison tobacco is 
not often to be recommended, but as a contact poison it is fre- 
quently the most cleanly, and is a favorite remedy in the green- 
house. Besides the methods already indicated, it may also be used 
in the form of smoke ; burning or steaming it, and sending the 
impregnated vapor into the conservatory or hot-house. Tobacco- 
smoke is quickly fatal to all insects that breathe it, but plants ex- 
posed to it for any great length of time are also likely to suffer. 
No specific directions as to the quantity of tobacco to be used 
can be given, and it will require practical experience to acquire 
the knowledge for each case. Good effects can be obtained in 
greenhouses by simply placing tobacco-stems on the benches, or, 
if the plants are potted, the pots may be set in a bedding of 
stems, or the stems may be kept upon the pipes heating the 
house, and this will give a sufficient impregnation to the air to 
discourage many insects, while there is no danger to plants. 



442 



A.V ECOXOMIC EXTOMOLOGY. 



This is especially ettective in houses that are kept ven- warm and 
moist. 

Standing on much the same plane is pyrethrum, or Persian 
insect powder," or "buhach," which is a Californian product. 
This is an exceedingly powerful contact poison, usually sold in 
the form of a finely ground, yellowish powder, with a not un- 
pleasant and somewhat pungent smell. Applied pure on most 
insects of moderate size, and especially on lan'^, it quicklv 
causes convulsions, and in most cases rapid death. It mav be 
mixed with two or three times its own bulk of cheap hour, and if 
the mixture is kept in tight jars for twenty-four hours, all parts 
of it will be equally efiective. It is especially adapted for use 
against plant-lice on a small scale, but is somewhat too expensive 
for use in the field, or on a large scale. In small conservatories 
nothing is better for general use. except against scale insects. 
Where the dry powder is undesirable for any reason, use a de- 
coction of an ounce in a gallon of water, first extracting with a 
quart of boiling water and then adding cold water. Most naked 
larv^ are rapidly afiected by this material : and while it is espe- 
cially a contact poison, yet it is also fatal when eaten, except 
in the case of large or adult insects. 

Among the contact poisons none ranks higher than kerosene, 
either pure or made into an emulsion with soap. Pure kerosene 
is fatal to almost aU insects : it is extremely penetrating, and 
works its way through the spiracles into the body cavity and 
through the trachea into all parts of it. This results in the prompt 
choking of the insect. Pure kerosene is more or less injurious to 
vegetation, although plants \-ary greatly in their resistance, and 
it is therefore advisable to mix it with water, which can be ac- 
complished by first emulsif\nng with either soap or milk. Prac- 
tically, milk is rarely used at the present time, as the soap 
formula is less expensive and. in general, more efiective. The 
following is the method of preparing the emulsion : 

Hard soap, shaved fine one-half pound. 

Water i gallon. 

Kerosene 2 gallons. 

Dissolve the soap in boiling water, warm the kerosene and add 
the boiling hot suds to it ; then churn with a force-pump for a 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 443 



few minutes, and we get first a milky appearance, which yields 
rapidly to a cream, and this to a soft butter-like mass. When 
cold, this will adhere to glass without oiliness, and the emulsion 
thus made, containing sixty-six per cent, of kerosene, may be 
readily mixed with water to any extent. It is also quite stable, 
and will remain unchanged for a considerable time. It is worthy 
of note that the emulsion is much more easily made with soft 
water, and if the water is very hard a permanent emulsion is 
difficult to procure. It is always advisable, therefore, to use 
rain-water, or to soften the hard water by adding soda or borax. 
Diluted from nine to twelve times, this emulsion is very effective 
against plant-lice, against many scale insects, and against a great 
number of others already referred to in previous chapters. Ex- 
cept in its pure condition, or in an almost undiluted emulsion, 
scale insects are not killed with certainty by kerosene, nor are 
insect eggs often affected ; yet the material has an extremely wide 
range, and is among the most useful of our contact insecticides. 

Another kerosene mixture is known as the " Cook emulsion," 
made as follows : 

Soft. soap I quart. 

Water 2 quarts. 

Kerosene i pint. 

Dissolve the soap in boiHng water and add, boiling hot, to the 
kerosene ; then churn as for the previous formula, and dilute 
with an equal bulk of water before using. This is effective in 
many cases as a mere soap-wash, and amounts to hardly more 
than the addition of a little kerosene to strong soapsuds. The 
formula is not recommended, except where the water is very 
hard and no rain-water is available. 

A combination of kerosene and pyrethrum has been made as 
follows : Percolate through one pound of pyrethrum one gallon 
of kerosene, or in that proportion, and use the extract in place 
of the pure kerosene : 

Hard soap i pound. 

Kerosene extract of pyrethrum i gallon. 

Water i gallon. 



Emulsify as before. 



444 



AN ECONOMIC ENTOMOLOGY. 



A modification, somewhat more easily prepared, is — 



Kerosene .... 
Hard soap . . . 
Pyrethrum powder 
Water 



I gallon. 
I pound. 
I pound. 
I gallon. 



Dissolve the soap in boiling water ; then add the pyrethrum, and 
stir, while continuing to boil, five minutes ; then add the kerosene 
and emulsify as before. 

This mixture has been found effective with dilutions of from 
four hundred to five hundred parts of water, but I have never 
been able to secure equally satisfactory results. Indeed, in my 
experience the pyrethrum adds little to the effectiveness of the 
emulsion. Yet I would not discourage experiments with the 
mixture, which may work better in other hands. 

Kerosene has also been used against scale insects on fruit- 
trees in winter by spraying the pure material and in about ten 
minutes setting fire to it. The kerosene burns off completely, 
taking with it scales, moss, and fungous growths generally. This 
use of it can be made on calm days only, as even a slow current 
of air is apt to blow the flame from one side, making the applica- 
tion ineffective. 

Gasoline, a much lighter oil, is useful as a contact insecticide 
in a limited number of cases. It can be apphed to textiles in- 
fested with ' ' moths, " or to carpets infested with ' ' carpet-beetles. ' ' 
It is very penetrating, kills everything it touches, and evaporates 
rapidly without influencing unfavorably any but the poorest fab- 
rics. The material is very inflammable, however, and this should 
be kept constantly in mind when using it. 

Soaps of various descriptions are useful contact insecticides, 
and act through the stigmata, or breathing pores, by clogging 
them and choking the insect to death. It is essential, to obtain 
a good effect from a soap mixture, that the application be ex- 
tremely thorough, so that each insect receives a complete coat- 
ing. There is a great variety of insecticide soaps on the mar- 
ket, but they all act in much the same way. In any good soap 
the suds are capable of being thinned out to an almost impercep- 
tible film, as we find in making soap-bubbles, and this, forming 
over the spiracles, resists the entrance of air. We cover the in- 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 445 



sects with a fine coating of soap, which, in drying, closes up the 
breathing pores, resulting in their death. It is thus that all 
soaps act when used against plant-lice, larvae, or adult insects, 
and it is readily seen that extreme thoroughness of application is 
desirable. 

After trying a large proportion of the soaps on the market, I 
have found nothing more effective for general use than good 
whale-oil soap : the term "whale oil" including any kind of fish 
oil that can be obtained cheap. The soap may be made by the 
farmer himself, according to the formulas given on every package 
of lye ; but, practically, the material is sold so cheaply that, un- 
less labor counts for nothing, it is as economical to buy as it is to 
make it. Whale-oil soap contains a considerable amount of 
caustic, and where a very thick suds is applied, we have not 
only the effect of the oil, but the prolonged effect of the caustic 
contained in it. It is, therefore, especially useful for destroying 
scale insects, against which caustics alone exercise a satisfactory 
effect. In whale-oil soap the caustic softens or lifts the scales, 
while the oil in the soap chokes the insect to death. To kill 
scales on trees it should be applied during the winter, when the 
vegetation is dormant, at the rate of two pounds in one gallon 
of water. To destroy plant-lice and most other insects feeding 
upon leaves, an extreme application is one pound in four gallons 
of water, which is as much as most plants will safely stand, and 
which is also effective against most of the insects upon which it 
can be used. Most plant-Hce yield readily to one pound in six 
gallons of water. In applying this material, thoroughness is es- 
sential, and it is the disregard of this necessary feature that often 
leads to failure. 

It sometimes happens that a really good fish-oil soap is not 
obtainable at a moderate price, and where it is desirable that a 
satisfactory effect be obtained against resistant scales like the 
San Jose, the following formula will make an effective material : 

Concentrated lye lYz pounds. 

Water 8 gallons. 

Fish oil I gallon. 

Dissolve the lye in boiling water, and to the boiling solution 
add the oil ; continue to boil for two and one-half hours, and then 



446 



A TV ECONOMIC ENTOMOLOGY. 



allow it to cool. This makes an exceedingly caustic soap, which 
is entirely reliable within its range of usefulness. 

Carbolic acid is also valuable as an insecticide, and can be used 
in the form of an emulsion prepared as follows : one pound of 
hard soap, shaved fine, dissolved in one gallon of boiling water, 
into which one pint of crude carbolic acid is then poured, and 
the whole mass made into an emulsion with a force-pump, used 
as in the case of the kerosene. This emulsion remains more or 
less stable for a long time, and can be diluted with thirty parts 
of water for effective use against certain classes of insects. It has 
been recommended for cabbage-maggots, and at the strength 
given will not injure the plants, w^hile it seems to be fatal to the 
young larvae. It is probably effective on soft-bodied insects in 
general, but it undoubtedly derives a considerable proportion of 
its effect from the presence of the large quantity of soap in the 
emulsion. 

Where lime is to be used as a repellent, the addition of one 
pint of crude carbolic acid to one hundred pounds of the dry 
hydrate wall increase its efficiency, and few insects will touch 
plants so protected. Among these few insects, however, we 
find the rose-chafer. 

The addition of carbolic acid to the whale-oil soap mixture is also 
advantageous in certain cases. One ounce of crude carbolic acid 
in each gallon of whale-oil soap mixture increases its effectiveness 
as against plant-lice very considerably. One pound of whale-oil 
soap in eight gallons of water, with four ounces of carbolic acid 
added, will double the effectiveness of the mixture ; but as the 
same result can be obtained with the soap alone in four gallons 
of water, it becomes a mere question of cost and simplicity. 

The whale-oil soap is often used in the form of a wash to pre- 
vent the entrance of borers into fruit-trees, and in such cases the 
addition of an ounce of the acid in a gallon of soapsuds seems to 
add to its efficiency. It is claimed that trees treated with such 
a mixture are much less attacked than those treated with the 
soap alone. A little lime is sometimes added to a liquid of this 
kind to make it more permanent. 

Lime alone is useful as an insecticide in some instances. It 
has been found effective by some and absolutely useless by 
others, the difference in result being often due to a difference 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 447 



in the method of application. As a rule, lime may be said to be 
effective in proportion as it is caustic, and it is then useful against 
soft-bodied insects. The best way to prepare it is to add just 
water enough to stone or shell lime to dry-slake thoroughly, then 
sift and apply the powder as soon as possible. This is more 
caustic than air-slaked lime, and wall burn a hole through the 
soft body of most larvae. I have seen it applied on the slugs of 
the potato-beetle in the morning while they were a little moist, 
resulting before noon in their complete destruction. So it may 
be applied to cabbages, and will in the same way destroy the 
larvae of the cabbage-butterfly. Lime is one of the best mate- 
rials for use on the larvae of the asparagus-beetle, and is also 
effective against the slimy or moist saw-fly larvae, including the 
" currant- worm." To obtain the best effects the lime should 
be dry and caustic, while the insects upon which it is appHed 
should be damp or slimy. Wherever a particle of lime sticks 
it will burn a hole into the insect. Few insects care to feed 
upon Umed vegetation, and many will not even rest upon a sur- 
face covered by it ; therefore, lime may be sometimes used as 
a repellent. Even the rose-chafer, when only moderately abun- 
dant, will generally avoid lime-dusted foliage. Whitewashing 
the trunks of trees will prevent the fixing of scale insects upon 
them, and will discourage borers from laying eggs on or boring 
into them. A free use of lime in every direction on the farm 
is advised. Against the striped melon-beetles use one pint of 
turpentine in one bushel of lime, applying freely to all parts of 
the plant, and particularly around the base. This will keep them 
off in most cases. 

In some of the Pacific States resin washes are much used 
against scale insects, apparently with excellent success. They 
have not been as satisfactory when used in the East ; perhaps 
due to the fact that the insects make thicker scales, or are more 
completely dormant in the winter. The wash which has given 
best satisfaction for summer use is made according to the follow- 
ing formula : 

Resin 20 pounds. 

Caustic soda (seventy per cent, strength) ... 5 pounds. 

Fish oil 3 pints. 

Water sufficient to make 100 gallons. 



448 



AN ECONOMIC ENTOMOLOGY. 



This mixture does not injure the trees or the foliage, and is 
effective against young scales. It kills all that are moving about 
in the larval condition, and also destroys recently fixed indi- 
viduals; but it is ineffective against mature scales and the in- 
sects under them. It acts by forming a thin varnish over the 
scales, thus seaHng up and choking them. In the mealy-bugs 
and cottony scales it mats up and seals the eggs so completely 
that the larvse find themselves unable to emerge, A stronger 
wash, used in winter, is made according to the following formula : 



Resin 30 pounds. 

Caustic soda (seventy per cent, strength) . . 9 pounds. 

Fish oil ^yi pints. 

Water sufficient to make 100 gallons. 



To make this mixture, boil all the ingredients together with 
twenty gallons of water until thoroughly dissolved, adding hot 
water from time to time, but not, after the boiHng begins, enough 
to stop it. Three hours will be required for a complete mixture 
of the materials, hot water to make fifty gallons being gradually 
added and the mixture thoroughly stirred ; after this the balance 
of one hundred gallons can be added in cold water. This is 
really a soap varnish, deriving its effect from the caustic and 
fish oil, while the resin forms an impenetrable covering. The 
stronger mixture, or "winter wash," cannot be used in summer 
without seriously injuring the foliage. 

Another wash frequently used on the Pacific coast, and found 
very effective against the San Jose scale and other insects, is a 
lime, salt, and sulphur mixture, made as follows : 



Unslaked lime 50 pounds. 

Sulphur 25 pounds. 

Stock salt 18 pounds. 

Water sufficient to make 100 gallons. 



This wash will do great damage to the trees if applied during 
the growing season, and should be used only in winter. All the 
sulphur and half the lime are placed in a kettle and twenty-five 
gallons of water added, after which the contents of the kettle 
are boiled briskly for an hour and a half, or until all the sulphur 
is thoroughly dissolved. The solution, which at first is yellow 



IXSECTICIDES, PREVENTIVES, AND MACHINERY. 449 



from the sulphur, will turn very dark brown, assuming more or 
less of a reddish tint, and will finally change from a thick batter 
to a thoroughly liquid condition, the product being ordinary 
sulphide of lime. All the salt is added to the remaining lime 
and the latter slaked, after which the slaked lime and salt are 
added to the sulphide of Hme already obtained, boiled an hour 
longer, the whole being then diluted with water to make one 
hundred gallons. This should be strained before application, as 
it does not form a perfectly Hquid solution, on account of the 
considerable quantity of undissolved lime, which will soon settle 
to the bottom unless the solution is constantly stirred while being- 
sprayed. A special nozzle with a rubber orifice is used for spray- 
ing this mixture in California. 

A modification, favored in Oregon, is, — 

Unslaked lime 100 pounds. 

Sulphur 100 pounds. 

Blue vitriol 8 pounds. 

Place all the sulphur and eighty pounds of lime in a kettle 
with one hundred gallons of water and boil slowly until the sul- 
phur is thoroughly dissolved. Dissolve the blue vitriol in hot 
water, add to the remainder of the slaked lime, and mix the 
whole together. This will keep any length of time. When 
ready to spray, use one gallon of the mixture in two and one- 
half gallons of hot water and apply lukewarm. It may be used 
as a summer wash by diluting one gallon with eight or ten gallons 
of water. 

These, though used successfully on the Pacific coast, have not 
proved as satisfactory in the East. They have been thoroughly 
tested by the agents of the Division of Entomology of the United 
States Department of Agriculture, who do not recommend them 
on the Atlantic coast. On the other hand, it should be said that 
the kerosene emulsion seems to be much less effective on the 
Pacific coast than it is in the East, and it is not unlikely that 
distinct sets of remedies must be used under different climatic 
conditions, these to be ascertained by direct experiments in the 
various localities. Progressive farmers will make it a point to 
get the bulletins of the Experiment Stations in their own States, 
to learn from them those facts which apply particularly in their 

29 



AJV ECONOMIC ENTOMOLOGY. 



own localities. The resin washes will not act well where frequent 
rains and much dew dissolve the varnish formed by them over 
the scales. 

Caustic potash and caustic soda, dissolved in water, are very- 
useful winter washes for fruit-trees. They can be used at the rate 
of one pound in one or two gallons of water, and will destroy all 
fungus growth and most of the common scale insects, leaving 
the bark pure, fresh, and glossy for the following season. Inci- 
dentally, all insects hiding under loose bark, or bark scales, are 
also destroyed, as are many insect eggs. The application should 
be confined to the trunk and larger branches, as there is danger 
to green bark in so strong a wash, and no foliage or active plant- 
tissue should ever be so treated. 

Water alone, either very hot or very cold, is sometimes a use- 
ful insecticide. Boiling water is quickly fatal to most insects 
and to vegetation as well. At 125° it is effective against the rose- 
chafer, killing it instantly, and at 140° it is still safe on grape 
foliage. At 160° it kills all vegetation on which I tried it. It 
has been applied with some satisfaction against cabbage-worms 
without injuring the plants, and perhaps we may say that water 
at a temperature of 125° is fatal to most insects and harmless to 
most plants. But while this seems a very convenient and cheap 
material, there are really grave practical difficulties in the way of its 
general use. Even boiling water applied in a spray becomes too 
cold twelve inches from the nozzle to be of any effect ; and so 
rapidly do the small particles lose heat, that at a distance of three 
feet it is reduced to atmospheric temperature. Its usefulness is 
limited, therefore, to cases where it can be applied at short range 
by a sprinkler, — e.g , on cabbage-plants ; and here the arsenites 
are cheaper and more certainly effective. 

Very^ cold or ice- water is effective against plant-lice under 
some circumstances, and I have known of trees and bushes com- 
pletely cleared by one appHcation. But our knowledge of the 
effects of cold on insects and plants is yet too small to make 
practical recommendations possible. 

Under some circumstances vapors can be made useful. Bi- 
sulphide of carbon volatilizes readily at ordinary temperatures ; 
the vapor is deadly to insects of all kinds, and is especially useful 
against species infesting stored products, like grain and other 



IXSECTICIDES, PREVENTIVES, AND MACHINERY. 451 

seeds. Where used in bins or closed receptacles, to kill insects 
infesting their contents, one drachm should be counted for each 
cubic foot of space, and a drachm may be roughly measured as a 
teaspoonful. It may be placed in an open vessel on top of the 
grain or other material, as the vapor, being heavier than the air, 
will descend to the bottom. It is also useful in many cases 
against plant-lice, and the range of the material has been already 
given in the various cases for which it is recommended. It is 
exceedingly inflammable and explosive, and in no building where 
the material is used should a light be allowed or a fire of any 
kind. Lighted pipes or cigars must be avoided, and even a 
spark may cause an explosion. With ordinary precautions, how- 
ever, the material is a useful one, since entire buildings can be 
treated at once. 

Hydrocyanic acid gas is another vapor exceedingly destructive 
to all hfe, but much more fatal to animals than to plants. It may 
be used for fumigating nursery stock or for destroying scale and 
other insects on trees. The vapor is produced as follows : in a 
glazed earthenware vessel place in the proportion of three fluid 
ounces of water and one ounce of ordinary sulphuric acid ; then 
add one ounce of fused potassium cyanide of ninety-nine per cent, 
strength. This will generate a very light and extremely poison- 
ous gas which is fatal to animal life of all kinds. The quantity 
above given suffices for one hundred and fifty cubic feet, and for 
a larger or smaller space a proportionate amount should be used. 
Trees to be treated with this gas must be covered by a tight tent 
of some kind, and for this purpose an eight-ounce duck, soaked 
with boiled linseed oil, may be used. Where shrubs or small 
trees are to be fumigated, a covered frame may be used and 
placed over the plants by hand ; but where large trees require 
attention, it will be necessary to have machinery mounted on 
wagons. In the chapter on insecticide machinery, one of these 
tents will be found figured. This hydrocyanic acid gas seems to 
be less fatal to plants and more effective against insects at night 
and in cool weather, and treatment at such periods is recom- 
mended ; or the tent may be painted black. It should never be 
used in hot weather during the middle of the day. This is 
another case where an insecticide seems to be more effective on 
the Pacific coast than in the East ; but it has not been sufficiently 



452 



AJV ECONOMIC ENTOMOLOGY. 



tested in the Atlantic States to make it possible to either encour- 
age or discourage its use. It has the advantage of being very 
thorough where it is at all effective, but the outfit required for 
large trees is expensive. 

Sulphur is an insecticide of comparatively limited range, but it 
seems in some cases to prevent injury and has almost a specific 
effect upon many of the mites which become troublesome in hot- 
houses. It is sometimes applied by dusting the flour of sulphur 
directly upon the plants, but is more usually applied in a watery 
mixture. Many nurserymen place a considerable quantity of 
crushed or powdered sulphur in a barrel and fill it with water, 
stirring at intervals, and allowing it to remain for days or even 
weeks, using from it and adding water as necessary. By boiling 
with lime, the sulphur can be entirely dissolved, and a more 
effective mixture will be obtained. In orange groves sulphur is 
largely used against the rust mite, and is effective by simply 
spreading it over the surface of the ground. It seems to cause a 
slow fumigation of the trees sufficient to destroy the mites. Cu- 
riously enough, this remedy seems less satisfactory on the 
Pacific coast than it has been found in the East. 

Gas-tar is sometimes recommended for certain purposes as an 
insecticide, and more frequently as a repellent ; but it is rarely 
of any practical value. It never serves to repel from any sur- 
face which it does not cover and mechanically protect, — that is to 
say, its odor will not prevent insects from attacking plants near 
it. It has been suggested that by placing it around the base of 
plants like squashes, the borers can be prevented from entering 
the plant ; but the moths will simply lay their eggs a little way 
from it, and the caterpillars, when hatched, bore into the stem at 
any point not actually touched by the tar itself Another 
method that has been recommended is to put a quantity of tar 
into a barrel and fill up with water ; then stir occasionally until 
the water becomes impregnated with whatever it can dissolve 
out. This, it has been said, is useful against plant-lice ; but I 
have never found any beneficial effects from it, and deem it of 
altogether too uncertain a value to be recommended. 

Naphthaline has been used as an insecticide, but is of compara- 
tively little value in the field, where its cost will prevent its gen- 
eral use. The vapor given off by it is offensive and even poi- 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 453 

sonous to many kinds of insects, so it may be used to protect 
against their attacks in stored products. It has been said that a 
sprinkhng of naphthahne crystals on the surface of grain recep- 
tacles will keep out all sorts of pests, and no doubt there is 
more or less basis for this claim. Naphthaline is used to keep 
museum pests out of boxes and cases containing specimens. 
Packed with clothing, woollens, or fabrics of any kind in a toler-^ 
ably tight box or closet, it will protect them from the attacks of 
"moths." 

Quassia, in the form of a decoction, has been recommended 
for insects of various kinds, noticeably plant-lice ; but, in my own 
experience, the results obtained have been so unsatisfactory that it 
would hardly pay to recommend it, when the soaps are so much 
more effective as well as less expensive. 

It remains to say a few v/ords on the subject of patented insect- 
icides, or mixtures sold under fancy names. As a general rule, 
such should be avoided. Many of them are more or less merito- 
rious, but in most instances they are paid for altogether too 
highly. In some cases the name has covered a mere mixture of 
Paris green and land plaster, charged for at many times its true 
value, and then advertised, besides, as being harmless. The 
range of the insecticides already mentioned will serve almost 
every purpose required by the farmer, and before using any pat- 
ented preparation, he should make an effort to ascertain just 
what material he is applying to his plants. It is also advisable to 
warn against the plausible schemes for preventing injury to trees 
and other plants by "inoculation," — that is to say, placing 
some substance into the body of the tree, with the idea that it 
will be carried into the circulation to repel insects that might be 
tempted to feed upon the foliage. All such preparations hereto- 
fore used have been frauds, and no benefit has ever resulted from 
any of them. In the same category belong those mixtures into 
which seed potatoes or other seeds are to be dipped or rolled to 
prevent the attacks of potato-beetles or other leaf-feeding insects. 



454 



AJV ECONOMIC ENTOMOLOGY. 



CHAPTER V. 

MACHINERY. 

Having determined the character of an injurious insect and 
the remedy to be applied, it remains to decide the method in 
which the appHcation is to be made, — i.e., whether the poison is 
to be used dry or in a watery mixture ; and this necessitates 
some information concerning pumps, nozzles, bellows, and the 
like. There is no better indication of the progress of economic 
entomology than the large number of firms now engaged in 
manufacturing and supplying machinery for the appHcation of 
insecticides. Every agricultural journal contains advertisements 
of such firms, and almost all of them issue illustrated catalogues 
describing their wares. It will be for the farmer, with the knowl- 
edge of his own requirements and necessities, to decide just what 
kind of an outfit he needs, and all that can be done here is to 
give a few suggestions as to the principles underlying the appli- 
cation of insecticides. 

Whether we apply dry powders or watery mixtures, the prime 
essential in all cases is thoroughness. Where poisons are to 
kill by contact, it is easily realized that contact is essential,— that 
is to say, that the insect must be actually touched by the poison 
to be at all effective. I have shown that such poisons kill in most 
instances by either entering the body through the spiracles or 
clogging them ; hence, also, the entire insect must be covered 
by the poison, if it is to be entirely effective. Where stomach 
poisons are to be used, it is equally essential that all parts of the 
plant be covered, so that, no matter how little the insect eats, it 
will yet obtain a poisonous dose. The amount of actual poison 
required to kill most insects is very small, but in order that they 
may obtain even this small quantity, the entire food-plant must 
be covered. The essential feature of a perfect machine for ap- 
plying insecticides is, therefore, that it shall quickly, thor- 
oughly, and economically distribute whatever poison is used. 
In some cases the application of dry poisons is desirable, though 
the method is often a wasteful one, besides involving a greater 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 455 

or less amount of expense for the diluting substance. Yet, when 
such an application is advantageous, we find that there are very 
few machines on the market for making it. The most elaborate 
and practical machine is the Leggett * ' Champion Powder-Gun, ' ' 
which, by means of a fan-blower, distributes dry insecticides in a 
very fine dust. With this machine, pure Paris green or London 
purple can be applied so thoroughly that all parts of a plant 
may be covered ; and as extension tubes and bent tips are fur- 
nished, small trees or high bushes can be conveniently reached. 
This is, I think, the best of the machines on the market for dis- 
tributing dry powders of all kinds. It is manufactured by Leg- 
gett & Brother, New York City, at a price of about $7.50. 

There is a variety of smaller bellows made by other manu- 
facturers, but they are scarcely practical for use on a large scale. 
Those sent out from the Hammond Slug-Shot Works are as 
satisfactory and as low in price as any, and the * ' Woodason 
Bellows," sold by most seedsmen and dealers in insecticides, are 
also effective on a small scale. In this short list the machinery 
for the application of dry powders is practically exhausted. There 
have been many other machines produced and patented, and in 
the reports of the United States Entomological Commission there 
are numerous cuts and figures of expensive dusting arrangements, 
none of which are in use at the present day. On the other 
hand, the tendency is all towards simplicity. A great many 
farmers who apply dry powders use the most rudimentary kinds 
of dusters, — perforated tin pans or the like. The cotton growers 
of the South have originated for their purpose a simple and very 
effective method of applying dry Paris green, and perhaps this 
will prove practical in other cases as well. It consists of a flex- 
ible, tough pole, to each end of which a coarse cloth sack, filled 
with pure Paris green or London purple, is tied. The stick is 
rested across the back of a mule, which is slowly driven between 
the rows of cotton, and the rider, striking continually with a 
short stick on the flexible pole bearing the bags, jars them suffi- 
ciently to dust out a very fine powdering of the poison. Practi- 
cally, this is the most satisfactory method of applying the arse- 
nites on cotton-plants that has been discovered, and it is now in 
almost universal use where poisons are applied against the cotton- 
worm. The method is extremely simple, and modifications of it 



456 



AN ECONOMIC ENTOMOLOGY. 



adapted to his special use will occur to any intelligent farmer. 
Applied through a sack, the dusting is exceedingly fine, while it is 
at the same time thorough, at least so far as the upper side of the 
leaves is concerned. 

It is in spraying machinery that the greatest advance has been 
made, and for a good spraying outfit there are two essentials, — a 
pump and a nozzle. The tank containing the spraying mixture 
may be almost anything, — a barrel, a tub, a box wagon, an elab- 
orate tank cart, or even a pail. What his receptacle shall be, 
each farmer may decide for himself The pump may also be of 
any type or pattern, provided that at least the working parts are 
of brass, because otherwise the corrosive poisons are apt to destroy 
it. For orchard work, or where large trees are to be sprayed, 
the pump should give a pressure of one hundred pounds or more, 
without requiring too much exertion. It should be double-acting 
to give a continuous stream, and should have an air-chamber of 
good size. The piston, or plunger, should not have too great a 
diameter, because the greater the diameter the greater the amount 
of force required to obtain a desired pressure. It must be re- 
membered that in ordinary spraying operations the object is not 
to throw the greatest possible amount of water in the least pos- 
sible time, but to obtain the greatest amount of pressure with the 
least expenditure of force. Force is to be looked for rather than 
quantity of discharge. There are many pumps upon the market 
fulfilling all the conditions above enumerated, and at various 
prices. 

Having selected the pump and mounted it upon any sort of 
tank, the next question is as to the nozzle to be used. What we 
want is the finest possible spray and the greatest possible amount 
of force, and these two requirements are more or less antagonistic. 
A very fine spray cannot be sent a great distance, and a jet 
capable of being sent into the top of a high tree is a wasteful 
method of application. There are, therefore, several types of 
nozzles adapted for somewhat different classes of work. By all 
odds the best, and the one having the greatest range of useful- 
ness, is the Vermorel modification of the "cyclone" or eddy- 
chamber nozzle. This consists, essentially, of a circular chamber 
into which the water enters from one side under pressure, receiv- 
ing thus a rotary motion. The point of exit is a single hole in 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 457 

the centre of a flat cap over the chamber. The water emerging 
from this opening under high pressure has a whirHng motion 
which produces a cone-shaped spray of exceeding fineness, de- 
pending upon the amount of pressure and the size of the opening. 
With a good pressure and an opening one-sixteenth of an inch in 
diameter, a fine mist-Hke spray can be sent a distance of ten feet, 
and this fulfils as nearly as possible the requirements of an ideal 
spray. In order that it may reach the tops of ordinary orchard 
trees, it is necessary that the nozzle should be elevated, and a va- 



FiG. 474. 




Vermorel nozzle and a section to show the working parts. 



riety of means are adopted to attain that end. In some cases, 
where extensive orchards of large trees are treated, the spraying 
is done from a tank cart, and sometimes from a little scaffolding 
built on it. More frequently, on moderate-sized trees, the hose 
is tied to a bamboo pole from ten to fifteen feet in length, and 
with this all such trees are easily reached. Instead of a bamboo 
pole with the hose attached, some farmers use a gas-pipe of 
proper diameter, to the end of which the nozzle is screwed. 
This is somewhat lighter, and the slender pipe is more easily 
managed. But all these are details which the agriculturist can 
arrange for himself A surprising amount of spray can be ob- 
tained from a nozzle of this kind with a very small actual expen- 
diture of liquid ; but where a great deal of spraying is done, two 
or three nozzles grouped at the end of a larger discharge pipe are 
sometimes used. The nozzles are so fixed that the spray is sent 
in all directions, and a very large area is covered by the poison 



458 



A AT ECONOMIC ENTOMOLOGY. 



in a very short time, A moderate-sized tree can be sprayed with 
a group of Vermorel nozzles in from one to three minutes. A 
good pump will easily supply two lines of hose, and most of 
those now made for orchard spraying are supplied with two dis- 
charge openings. A three-quarter hose is all that is necessary, 
even when a compound nozzle is used. The Vermorel nozzle 
is supplied with a ' ' degorger, ' ' or apparatus for cleaning out 
the spray opening in case it becomes clogged ; but it is not 
easily clogged, and is, in fact, one of the most satisfactory from 
that stand-point. With a screen at the bottom of the suction 
pipe the meshes of which are not larger in diameter than the dis- 
charge opening in the nozzle, clogging should be practically im- 
possible. 

Fig. 475. 




The Nixon nozzle.— i, complete ; 2, 3, the two parts, separated. 



The Nixon nozzle is a satisfactory bit of apparatus, working 
on an entirely different principle from the cyclone. Here we 
have a barrel-shaped cylinder of varying length, at the base of 
which the water enters through a small opening in a solid jet, di- 
rected against a wire screen at the tip of the cylinder. With a 
good force behind it, a fine spray is sent from such a nozzle from 



IXSECTICIDES, PREVENTIVES, AND MACHINERY. 459 



ten to fifteen feet. This nozzle has proved very satisfactory in 
orchard work, but has the disadvantage of clogging very much 
more readily than the cyclone, and of not clearing easily when 
it does clog. With a proper netting at the end of the suction 
pipe, the tendency to clog can be reduced to a minimum, and 
with a Httle practice in actual field work, the nozzle has proved 
satisfactory . 

The McGowen nozzle is of yet a different type, and throws a 
fan-shaped spray the quantity of which can 
be varied by adjusting a spring which regu- 
lates the size of the opening. The nozzle 
has the advantage of being self-clearing, — 
that is to say, any obstruction which may 
lodge at the opening creates a pressure 
sufficient to overcome the strength of the 
spring, and the vent broadens sufficiently 
to allow the escape of anything that can 
get into the barrel of the nozzle. As soon 
as the obstruction is removed, the spring 
restores the opening as originally set. The 
peculiarities of this nozzle are that the spray 
can be thrown a much greater distance than 
with any of the types previously mentioned, 
and that the amount of liquid to be dis- 
charged can be regulated. It has certain 
advantages, therefore, in an orchard where 
large trees are to be treated, but it does 
not throw as fine a spray over so great a 
surface as the Vermorel. 

For spraying very large trees many 
growers have found a cheap graduating 
nozzle effective. This is a cylinder with 
a large flared opening, through which a 
conical pin may be forced, even to its com- 
plete closure. When the pin is completely The AicGowen nozzle 
retracted, which is done by turning the ^ ^^^^^i"" through its 

. . tip to show working- parts. 

barrel of the nozzle, a solid jet is thrown, 

and any intermediate grade between this and a tolerably fine 
spray may be readily obtained. For spraying shade-trees nothing 





460 



A AT ECONOMIC ENTOMOLOGY. 



Fig. 477- 




is more satisfactory than this, because it gives the greatest range 
in distance and in quantity of discharge. Even if the spray is 

coarser than with the other nozzles, 
the work is more rapid. Practically, 
it will not be necessary to go beyond 
the nozzles already described to ob- 
tain satisfaction. 

The Vermorel modification of the 
cyclone nozzle is manufactured by 
almost all makers of insecticide 
machinery, and can be obtained 
anywhere. The graduating nozzle 
may be purchased in almost any 
hardware store, or wherever lawn 
sprinklers and garden hose supplies 
are sold. The Nixon nozzle is 
patented, and obtainable from the 
Nixon Nozzle and Machine Com- 
pany, Dayton, Ohio, or from their 
agents. The McGowen nozzle is 
also patented, and obtained only 
from J. J. McGowen, Ithaca, New York. There are many other 
nozzles on the market, all of which have certain advantages, 
from which the farmer must himself select those most useful to 
him. So there are special nozzles for certain purposes, as that 
for spraying the lime, salt, and sulphur mixture used on the 
Pacific coast. All these are advertised by dealers in spraying 
machinery, so that the intending purchaser can secure full in- 
formation. 

For spraying certain field crops on a large scale — e.g., pota- 
toes—there is a tendency to use geared machines, — that is to say, 
tanks mounted upon a cart, and the pump geared to the axle, so 
that in simply driving through the field it will be operated. Then, 
by means of an extension rod fitted with nozzles, from four to 
six rows of potatoes or other plants can be sprayed at one time. 
Several manufacturers make machines of this character, and a 
great many of them are in use, giving satisfaction, as a rule. 
They have the advantage of covering a great area in a very short 
time, and reducing the cost of spraying to a minimum, doing the 



A graduating nozzle. 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 461 

work evenly and with little chance of missing. Where a large 
acreage of potatoes is grown, one of these machines is almost in- 
dispensable, and with it the potato-beetle can be kept in check 
very readily. Of course these machines may also be used for 
applying fungicides on the same plants. Geared machines should 
never be used in spraying orchards ; or, if they are, the gearing 
should be thrown off and the pump operated by hand. It is 
practically impossible to spray orchard trees thoroughly by 
simply driving between the rows and directing the spray from the 
wagon to the trees as they are passed. If this is done, slipshod 
work is apt to result which will not be effective, so that both 
labor and money will be wasted and the spraying might as well 
be omitted. 

Of a somewhat distinctive type is the Bean spray pump, which 
forms a spray by air-pressure, and is, indeed, practically an 
atomizer. It is somewhat complicated, and has not found favor 
in the East, though considered a satisfactory machine on the 
Pacific coast. It is an apparatus not likely to clog, and the spray 
produced by it leaves little to be desired. I have not seen it in 
actual service, hence cannot say how well founded is the charge 
of difficulty of manipulation. 

* ' Knapsack pumps' ' have come into very general use of recent 
years, and quite a variety are now manufactured, — all built upon 
one general plan. There is a copper tank, holding usually in 
the neighborhood of five gallons, and a double-acting pump con- 
cealed within the tank itself, and operated by a lever that passes 
either under the left arm or over the left shoulder. These knap- 
sack pumps may be used for a very great range of work. As a 
rule, they have a short discharge hose and a brass rod or ' ' lance' ' 
terminating in a Vermorel nozzle. The lance varies in length, 
but its extreme is about thirty-six inches, so that low plants may 
be easily reached while the worker is standing upright. In the 
apparatus furnished by Boekel & Co., of Philadelphia, the nozzle 
is adjustable in such a way that the spray may be sent in any 
direction. If the under side of low plants is to be reached, the 
nozzle is simply set so as to spray upward, and in fact it can be 
adjusted so as to do almost any kind of work required in the 
field and vineyard. For the grower of small fruits, including 
grapes, a knapsack pump is almost indispensable. Bush fruits 



462 



AJV ECONOMIC ENTOMOLOGY. 



like currants, gooseberries, blackberries, and raspberries can be 
most satisfactorily reached by a machine of this kind, because it 
can be easily operated wherever the operator himself can go. 

There are many good, simple pumps now on sale, some of them 
single-acting, — little more than a syringe, in fact ; others double- 
acting, and throwing a fairly good jet for considerable distances. 
These are usually termed "bucket pumps," and are satisfactory 
in some cases, but are rarely advisable where work is to be done 
on anything like a large scale. A good bucket pump is very 
desirable, however, where kerosene emulsion is to be made, and 
it will easily pay for itself, by facilitating the preparation of this 
material, if it is to be used in quantity. With a good bucket 
pump three gallons of emulsion may be made in five minutes 
after the soapsuds have been heated to the boihng-point. 

This is hardly the place to recommend makers of insecticide 
machinery or machines of special types. The farmer, before 
purchasing, should look through the advertisements in his farm 
papers, and write for catalogues to those advertising spraying 
machines. From these catalogues he should be able to select 
a proper outfit for his special purpose, keeping in mind the 
recommendations that have been made in this chapter. There 
is, however, one warning that must be given : the cheapest outfit 
is not always the one that costs the least money ! Durability 
should be looked to as well as effectiveness and simplicity of 
structure, so that if there is anything out of order it can be 
readily repaired by the farmer himself Strength is desirable in 
all the parts, and the structure of the valves and the character of 
the packing should be looked to. Cheap pumps, as a rule, have 
unreliable valves and ordinary cotton packing. The best pumps 
have brass valves and metal packing, so that, except in cases of 
accident or extreme carelessness, repacking is not required for 
years, if at all. In fact, a pump should be selected just as care- 
fully as any other piece of machinery, and when a proper outfit 
is purchased, it should be studied until it is thoroughly under- 
stood. It will then be possible to use it with satisfaction, and the 
results are apt to be good. 

There is now upon the market a machine to avoid making 
an emulsion where kerosene is to be used, by providing for a 
mechanical mixture of kerosene and water in the proper propor- 



INSECTICIDES, PREVENTIVES, AND MACHINERY. 463 



tions in the act of spraying. At the present writing this machine 
is not sufficiently perfected to warrant me in recommending it, 
but no doubt practical machines will be constructed, in the near 
future, carrying kerosene in one tank and water in another, with 
a pump so arranged that the materials will combine in a mechani- 
cal mixture that can be satisfactorily applied to plants. 



Fig. 479- 




An " emulsion" knapsack sprayer for combining kerosene and water. 

For applying insecticides underground, which is sometimes 
desirable in using bisulphide of carbon against the cabbage-root- 
maggot and other subterranean species, there is only one satis- 
factory piece of machinery, — the McGowen injector. This is best 
explained by Fig. 481, illustrating its use on cabbages. The fol- 
lowing directions may be observed, and will at the same time 
indicate the method in which the machine may be used for other 
purposes. 

The method of inserting the injector is shown in Fig. 481. 
The hole should always begin at a distance of three or four inches 



P^IG. 481. 



Fig. 480. 




INSECTICIDES, PREVENTIVES, AND MACHINERY. 465 

from the plant, and run horizontally downward to a point a little 
below the roots. To accomplish this the injector must be inserted 
at an angle, as shown in the figure. Force it down until the 
point is a little below the roots, then let out the charge of liquid. 
In operating the injector, first pull the piston up as far as it will go. 
This loads the measuring chamber between the valves. Then 
push down the piston until it stops, and the instrument is ready 
to be pushed into the ground. Push it into the ground as far as 
desired. Hold it there while you pull up the piston. By this 
operation you let the charge out of the lower chamber into the 
ground, and at the same time the measuring chamber is again 
filled. Hold the injector in the ground a few seconds after the 
piston has been pulled up, in order that all the liquid in the 
charge may have a chance to run out. Then pull the injector 
out of the ground, and quickly, with the foot, fill the hole with 
earth and step on it to pack it down. Press down the piston, 
and you are ready to treat the next plant. Never push the 
injector into the ground unless the piston is clear down, because, 
if the lower end is not thus closed, it will immediately fill with 
soil, which is not easily removed. Study the drawings in Fig. 
480, in connection with these directions, and you will under- 
stand the reason for each step. We would advise that the reser- 
voir be first filled with water and the injector operated above the 
ground until each step is thoroughly understood. There is 
nothing complicated about the instrument or the way it is to be 
operated. It can be easily taken apart and cleaned, if necessary ; 
the only caution to be observed in replacing the parts is to have 
the flanges of the leather in the upper valve turned upward. 
The injector is made by John J. McGowen, Ithaca, New York. 

Under this head we may refer to the ''hopper-dozers" which 
have been recommended against certain Hemiptej'a and Orthop- 
tera. These are simply shallow pans of thin sheet-iron, of con- 
venient length for the special use intended, mounted on runners 
so high as to bring the bottom of the pan to the top of the vege- 
tation to be treated. The runners can easily be made adjustable in 
height by any clever mechanic. The front of the pan is turned 
up enough to prevent its cutting or otherwise injuring vegetation, 
and the sides are also turned up at least two inches and the cor- 
ners made sufficiently close to hold water, if necessary. Along 

30 



466 



AiV EC 0X0 MIC ENTOMOLOGY. 



the hinder edge is stretched a canvas-covered, upright frame, at 
least twelve inches high, which prevents grasshoppers from jump- 
ing over the machine. The ' ' dozer' ' may be drawn by man or 
by horse-power, and when in use the bottom is covered with crude 
petroleum, or with water on which is floated a film of kerosene. 
The canvas-covered frame is also moistened with kerosene. As 
the apparatus is drawn through the fields the insects jump up 
before, and usually, in trying to leap over, fall into it. Even if 
they jump out again immediately, they are doomed, because 



Fig. 482. 




Hopper-dozer"' for man-power. 



once wet with kerosene they die in a few minutes. These 
machines are useful only on comparatively level ground, but they 
often destroy great numbers of injurious insects when properly 
handled. 

Finally, we may say a few words concerning fumigating appa- 
ratus. No two outfits are quite alike, and the work to be done 
must in ever}^ case determine the character of the machinery. 
The essentials are a gas-tight tent, and a means of placing it over 
the plants to be fumigated. The method of producing the gas 
is elsewhere described. For the tent, eight-ounce duck, saturated 
with boiled linseed oil, is recommended, and it should be made 
to close so tightly that little gas can escape through the lap. As 
for the machinery to place it over the tree, that must be in all 
cases determined by the circumstances ; but Fig. 483 will give an 
idea of- the way things are done in California. The outfit is an 
expensive one, and will pay only when an entire neighborhood 
can be suppHed by it. 



Fig. 483. 




The Wolfskin fumigator. 



INDEX. 



Abdomen, how made up, 26. 
Acanthia lectularia, 155. 
Achatodes zeae, 299. 
Acrididae, defined, 85. 

life histon', 89. 
Acridium species, 89. 
Acronycta americana, 289. 
Actias luna, 282. 
Aculeata, defined, 390. 
Adalia bipuncta, 174. 
Adephaga, defined, 165. 
Agallia sanguinolenta, 147, 
Agaristidae, 264. 
Agricultural ants, 398. 
Agrilus ruficollis, 186. 

sinuatus, 187. 
Air-sacs or bladders, 36. 

-tubes, extensile, 37. 
Alaus oculatus, 183. r 
Alder-blight, 133. 
Aletia argillacea, 301. 
Aleyrodes citri, 122. 
Aleyrodidae, 121. 
Allorhina, species, 203. 
Alulet, 365. 

Alypia octo-maculata, 263. 

Ambulatoria, 81. 

American blight, 133. 

Amm. solution of copper carbonate, 439. 

Amphicerus bicaudatus, 195. 

Anabrus simplex, 97. 

Anal glands and secretions, 30. 

Anasa tristis, 160. 

Anatis 15-punccata, 174. 

Andrena species, 411. 

Angoumois grain moth, 326. 

Anisopteryx species, 307. 

Anisota senatoria, 278. 

Anomala lucicola, 202. 



Anomis species, 300. 
Antennas, function of, 20. 

general characters, 19. 
Anthocoridas, 156. 
Anthomyiids, 360. 
Anthonomus 4-gibbus, 232. 

signatus, 231. 
Anthrax, species of, 345. 
Anthrenus scrophulariae, 179. 
Ant-lions, 76. 
Ants, described, 390. 

and plant-lice, 127, 394. 
Apanteles species, 383. 
Aphaniptera, 328. 
Aphelinus mytilaspidis, 385. 
Aphididae, 123. 
Aphidius species, 384. 
Aphis-lions, 74. 

mali, 134. 

parasites, 383. 

persicas-niger, 134. 
Aphodius, 198. 
Apis mellifica, 414. 
Apple, Anthonomus on, 232. 

blight-louse, 133. 

case-bearer, 324. 

codling moth on, 322. 

fiat-head borer in, 186. 

leaf-crumpler, 313. 

long-horned twig-borers, 209. 

-louse, 134. 

-maggot, 366. 

oyster-shell scale on, 115. 

round-head borer in, 209. 

tree-hoppers on, 138. 

twig-borer, 195. 

yellow-neck caterpillar, 275. 
Aquatic forms, how they breathe, 36, 
Aramigus fulleri, 228. 

467 



468 



INDEX. 



Arbor-vitas, bag-worm on, 273. 
Arctiidse, 266. 
Argynnis species, 244. 
Arista of flies, 330. 
Armored scales, 114. 
Army- worm, 294. 
Arsenate of lead and its use, 436. 
Arsenic as an insecticide, 437. 
Arsenites and their use, 434, 438. 
Ascalaphus species, 76. 
Asilidae, 344. 
Asopia costalis, 312. 
Asparagus beetle, 211. 
Aspidiotus perniciosus, 118. 
Atomaria species, 177. 
Atropos species, 69. 
Attacus species, 279, 
Auditory sense of insects, 43. 
Automeris io, 283. 

Bag-worms, 273. 
Balancers of flies, 327. 
Balaninus species, 234. 
Bandings of printers' ink, etc., 433. 
Bark-beetles, 237. 

-slippers, 207. 
Beak of bug mouth, 16. 
Bean lady-bird, 175. 

-weevils, 223. 
Bean spray pump, 461. 
Bed-bug, 155. 
Beech blight, 133. 
Bees, 407. 

long- and short-tongued, 410. 
Bee-flies, 345. 

-louse, 370. 

-moth, 316. 

mouth, 19. 
Beet-leaf magots, 365. 
Beetles, chapter on, 164. 

classification of, 165. 
Bell moths, 319. 
Bellows, 455. 

Belostoma americana, 150. 
Bembecia marginata, 260. 
Bembecidse, 403. 
Bibionidae, 340. 
Bichloride of mercury, 438. 
Bill-bugs in corn, 236. 



Bipectinated antennae, 21. 
Bisulphide of carbon, 450. 

against hen-lice, 71. 

against Termites, 67, 
Biting lice, described, 70, 
Bittacus, 77. 

Black beetles, their habits, 82. 
Blackberry cane-borer, 186. 

crown-borer, 260. 

pithy gall, 378. 

root-borers, 206. 

saw-fly borer, 375. 
Black flies, 340. 
Blattidse, described, 81. 
Blennocampa p3^gmaea, 374. 
Blissus leucopterus, 158. 
Bhster beetles, 225. 
Blood of insects, 33. 
Blow-fly, 257. 
Blues and coppers, 245. 
Body-louse, life history, 105. 
Boll- worm, 303. 
Bombardier beetles, 168. 
Bombyliidae, 345. 
Bombylius species, 345. 
Book-lice, 68. 
Borax, against roaches, 82. 
Bordeaux mixture and its uses, 
Boreal lady-bird, 175. 
Borers, remedies for, 188. 
Boreus, 77. 
Bostrychus, 193. 
Bots on cattle, 352. 
Bot-flies, 351. 
Brachinus, 168. 
Brachystola magna, 91. 
Braconidae, 382. 
Brain in insects, 39. 
Bran and Paris green, 438. 
Braula c^ca, 370, 
Breast-bone of gall-gnats, 336. 
Breathing of insects, 33. 
Bristle-tails, 53. 
Bristled antennae, 22. 
Bruchidae, 223. 
Brush-footed butterflies, 242. 
Bucket-pumps, 462. 
Buffalo gnat, 340. 

grasshopper, 91. 



INDEX. 



Buffalo moth, 179. 

tree-hoppers, 138. 
Bugs, defined, 100. 
Buhach, 442. 
Bumble-bees, 411. 

life history, 416. 
Buprestidae, 185. 
Buprestis, 185. 
Butterflies, chapter on, 240, 

classified, 241. 

mouth of, 16. 
Byturus unicolor, 180. 

Cabbage butterflies, 246. 
harlequin bug on, 162. 
-lice, 134. 
-maggot, 361. 
Plusia, 302. 
thrips, 102. 

-worms, parasites on, 385. 
Cacoecia fervidana, 321. 

rosaceana, 321. 
Caddice-flies, 77. 
Cadelles, 182. 

Caecal tubes or pouches, 30. 
Calandra, species of 237. 
Calliphora vomitoria, 357. 
Camel crickets, 97. 
Canker-worms, 307. 
Capsidae, 156. 
Carabidae, 166. 

Carbolic acid and its uses, 446. 
Carbon disulphide and its uses, 450. 
Carnivorous beetles, 165. 
Carolina locust, 88. 
Carpenter ants, 391. 

bees 412. 
Carpet beetle, 179. 
Carpocapsa pomonella, 322. 
Carpophilus hemipterus, 181. 
Carrion beetles, 171. 
Cassida bivittata, 222. 
Cassidae, 222. 
Catch crops, use of 426. 
Caterpillar hunters, 168. 
Catocala species, 306. 
Caustics, how they kill, 39. 
Caustic potash and soda washes, 450. 
Cecidomyia destructor, 336. 



Cecidomyia leguminicola, 338. 
Cecidomyidae, 336. 
Cecropia moth, 280. 
Cephalo-thorax, defined, 34. 
Cephus pygmseus, 376. 
Cerambycidae, 205. 
Ceraphron triticum, 388. 
Ceratocampid^, 278. 
Ceratomia amyntor, 257. 
Ceratopogon species, 334. 
Ceratopsyllus serraticeps, 329. 
Ceresa bubalus, 139. 
Cerci, defined, 26. 
Cercopidae, defined, 146, 
Ceroplastes, 112. 
Chaetocnema confinis, 219. 
Chalcididae, 384. 
Chalcophora, 185. 
Chauliodes pectinicornis, 72. 
Chauliognathus, 191. 
Chermesinas, defined, 128. 
Cherry-louse, 134. 
Chestnut weevils, 234. 
Chicken-fleas, 329. 

-lice, 71. 
Chickens versus insects, 426, 
Chilo species, 317. 
Chilocorus bivulnerus, 174. 
Chinch-bug, fife history, 158. 
Chinese silkworm, 286. 
Chionaspis furfurus, 119. 
Chironomidae, 333. 
Chitine, peculiarities of 14, 38. 
Chortophaga viridifasciata, 88. 
Chrysalis, defined, 50. 
Chrysanthemum fly, 348. 
Chrysididas, 390. 
Chrysobothris, 186. 
Chrysomelidse, 205,210. 
Chrysopa, 74. 

Chrysophanus, species of 245. 
Chylific ventricle, 30. 
Cicada, defined, 139. 

septendecim, 140. 
Cicindelidae, 166. 
Cigarette beetle, 193. 
Ciliated antennae, 22. 
Cimbex americana, 374. 
Circulation in insects, 33. 



470 



INDEX. 



Citheronia regalis, 278. 
Classification in general, 52. 
Clavate antennae, 21. 
Clavicornia, defined, 165. 
Cleanliness, to check insects, 423. 
Clear-wing moths, 259. 
Cleridae, 192. 
Clerus apivorus, 192. 
Chck-beetles, 182. 
Climbing cut-worms, 292. 
Clisiocampa americana, 284. 
Clothes moths, 324. 
Clothilla, 69. 
Clothing of bees, 408. 
Clover hay-worm, 312. 

leaf-beetle, 229. 

seed-midge, 338. 

stem-borer, 176. 
Coccidae, defined, 106. 
Coccinella 9-notata, 174. 
Coccinellidae, 172. 
Cochineal insect, 106. 
Cockchafer, 201. 
Cockscomb gall on elm, 132, 
Cocoon, described, 50. 
Codling moth, 322. 
Coleoptera, defined, 54, 55. 

chapter on, 164. 

classification of, 165. 
Colias philodice, 250. 
Colon, described, 30. 
Colopha ulmicola, 132. 
Colorado potato-beetle, 213. 
Commercial fertilizers as insecticides, 
427. 

Complemental sexes of Termites, 66. 
Complete metamorphosis, 50. 
Compound eyes, 42. 
Cone-nosed grasshoppers, 96. 
Conocephalus, 96. 
Conopidse, 351. 
Conorhinus sanguisuga, 152. 
Conotrachelus crataegi, 234. 

nenuphar, 232. 
Contact poisons, how they act, 38. 
Cook emulsion, 443. 
Coppers and blues, 245. 
Copris Carolina, 198. 
Coptocycla aurichalcea, 223. 



Coreid^, defined, 160. 
Corimelasnidas, defined, 163. 
Corn bill-bugs, 236. 

-root Diabrotica, 215. 

-root-louse, 134. 

-root web-worm, 317. 

-worm, 303. 
Cornicles, defined, 126. 
Corisa, habits of, 150. 
Coriscus, 153. 
Corrodentia, 68. 
Corrosive sublimate, 438. 
Corticaria, 177. 
Corydalus cornutus, 72. 
Corynetes rufipes, 193, 
Cossidae, 286. 
Cotalpa lanigera, 202. 
Cotton boll-worm, 303. 

red-bug on, 157. 

-stainer, 157. 

-worms, 300. 
Cottony cushion scale, 108. 

maple scale, no. 
Cow-lice, how destroyed, 71. 
Coxa, defined, 26. 
Coxal cavity, defined, 26. 
Crab-louse, 105. 
Crambids, 316. 
Crambus species, 317. 
Cranberry fire- worm, 320. 

fruit-worm, 313. 

span-worm, 309. 

Teras, reflowing for, 428. 
Crane-flies, 330. 
Cremastogaster lineolata, 392. 
Crepidodera, 219. 
Crickets, 97. 
Crioceris asparagi, 211. 

i2-punctatus, 211. 
Crop, described, 30. 

of lepidoptera, 31. 
Crop remnants should be removed, 424. 
Croton bugs, 82. 
Cruciferous weeds, lice on, 134. 
Cryptophagus, 177. 
Cuckoo-bees, 390. 
Cucumber caterpillar borer, 311, 

flea-beetle, 219. 

striped beetle, 214. 



INDEX. 



471 



Cucujidae, 176. 
Culicidae, 332. 

Cupram, use and formula, 439. 
Curculio, defined, 228. 
Currant borer, 263. 

4-lined plant bug on, 156. 

long-horned borer in, 208. 

worm, 372. 
Cursoria, defined, 81. 
Cuterebera emasculator, 352. 
Cut-worms, life history, 290. 

remedies for, 293. 
Cyclone nozzle, 456. 
Cydnidae defined, 162. 
Cyllene pictus, 208. 

robiniae, 208. 
Cymatophora pampinaria, 309. 
Cynipidae, defined, 376. 
Cyrtophyllum concavum, 94. 

Dagger moths, 289. 
Danais archippus, 242. 
Darkling beetles, 224. 
Dascyllidae, 182. 
Datana ministra, 276. 
Day-flies, 59. 
Death-watch, 69. 
Delta moths, 306. 
Deltoids, 306. 

Dendrolene and raupenleim, 431. 
Dermaptera, 79. 
Dermestes lardarius, 178. 

vulpinus, 178. 
Dermestidae, 178. 
Devil's darning-needles, 60. 
Diabrotica longicornis, 215. 

i2-punctata, 215. • 

vittata, 214. 
Diapheromera femorata, 86. 
Diaspinae, defined, 114. 
Diaspis rosae, 119. 
Diastrophus nebulosus, 378. 
Diatraea saccharalis, 318. 
Dicerca, 185. 

Dictyophorus reticulatus, 91. 
Digestive system, described, 28-30. 
Digger wasps, 399, 403. 
Diplosis pyrivora, 339. 
tritici, 338. 



Diptera, chapter on, 327. 

defined, 54, 55. 
Diseases of insects, 418. 
Dissosteira Carolina, 85. 

longipennis, 85. 
Dobson, 72. 
Dog-flea, 328. 
Dorsal surface, 25. 
Dorsum, is upper surface, 25. 
Doryphora lo-hneata, 213. 
Dragon-flies, 60. 
Drasteria crassiuscula, 305. 

erechtea, 305. 
Drone-fly, 348. 
Drosophila species, 367. 
Dryocampa rubicunda, 279. 
Dry powders, how applied, 454, 

how they kill, 39. 
Dynastes, 203. 
Dysdercus suturellus, 157. 
Dytiscidae, 169. 

Ears of insects, 43. 
Earwigs, life history, etc., 79. 
Economic entomology, development of, 
9- 

Ectobia germanica, 82. 

Edema albifrons, 277. 

Eggs, number laid by insects, 45. 

of mantidae, 84. 

of roaches, 81. 

stage described, 48. 
Eight-spotted forester, 263. 
Elaphidion species, 207. 
Elateridae, 182. 
Electric-light bugs, 151. 
Elm, cockscomb gall on, 132. 

leaf-beetle, 217. 

4-horned sphinx on, 257. 
Elytra, 164. 
Emasculating bot, 352. 
Empretia stimulea, 271. 
Enemies of insects, 45. 
Ephemeroptera, described, 59. 
Ephestia ktihniella, 315. 
Epidapus scabei, 335. 
Epicauta cinerea, 227. 

pennsylvanica, 227, 

vittata, 225. 



472 



INDEX. 



Epidemics among insects, 45. 
Epilachne borealis, 175. 

corrupta, 175. 
Epipharynx, function of, 15, 43. 
Epitrix, 219. 
Eriocampa cerasi, 372. 
Eristalis tenax,348, 350. 
Erotylidae, 175. 
Erythroneura vitis, 148. 
Euchromia ipomaeae, 264. 
Eucleidae, 271. 
Eumenes, nests of, 404. 
Euphoria inda, 204. 
Euplexoptera, 79. 
Eupogonius, 209. 
Eurycreon rantalis, 311. 
Eyes, compound, 22. 

of insects, 41. 

Fall army-worm, 297. 

plowing, effect of, 425, 

web- worm, 266, 
Family, defined, 52. 

Farm practice to prevent insect attack, 
423- 

Feather-wing moths, 318. 

Feeding habits, how determined, 14. 

Feelers are antennas, 19. 

Femur, defined, 26. 

Fenesica tarquinius, 246. 

Fertilizers as insecticides, 427. 

Fidia viticida, 211. 

Filicornia, defined, 165. 

Filiform antennae, 21. 

Fire-flies, described, 190 

Fish-moth, 53, 56. 

-oil soap, use and formula, 445. 
Flat-head borers, 185. 
Flax-seed stage of Hessian fly, 336. 
Flea-beetles, 219. 
Fleas, described, 328. 
Flesh-flies, 356. 
Flies, chapter on, 327. 
Flower-beetles, 192. 

-flies, 347. 
Fly, experiments with, 41. 
Foraging ants, 399. 
ForficuHdae, defined, 79. 
Formicidae, 391. 



Fossores, 399. 
Four-lined plant-bug, 156. 
Fowls, affected by lice, 71. 
Frog-hoppers, 146. 
Fruit bark-beetle, 238. 
Fulgoridae, defined, 146. 
Fuller's rose-beetle, 228. 
Fumigating apparatus, 465. 
Funicle of antenna, 22. 
Fungus diseases of insects, 418, 422. 
gnats, 334. 

Galeruca xanthomelaena, 217. 
Gall-flies, 376. 

-gnats, 336. 

-hce, described, 132, 
Galls, ink from, 378. 
Galleria melonella, 316. 
Ganglia, described, 39. 
Garden web-worm, 3x1. 
Gas-tar as an insecticide, 452. 
Gasoline as an insecticide, 444. 
Gastrophilus equi, 351. 
Geared machines, 460, 
Gelechia cereallella, 326. 
Geniculate antennae, 22. 
Genus, defined, 52. 
Geometridae, 307. 
Geotrypes, 198. 
Gills, of aquatic insects, 37, 
Gizzard, described, 30. 
Glow-worms, 190. 
Gnats. 334, 340. 
Goat-moths, 286. 
Goldsmith beetle, 202. 
Gouty gall on blackberry, 186, 
Graduating nozzle, 459. 
Grain-weevils, 237. 
Grape, American Procris on, 264. 

chafers on, 202. 

8-spotted forester on, 263. 

flea-beetle, 219. 

leaf-hopper, 148, 

phylloxera, 128. 

plume-moth, 318. 

Pyrophila on, 299. 

-root-worm, 206, 212. 

-slug, 373. 
Grapta comma, 244. 



INDEX. 



473 



Grass, leaf-hoppers in, 147. 

thrips on, 102. 
Grasshoppers, hfe-history, etc., 89. 

long-horned, 93. 

short-horned, 85. 
Green-striped locust, 88. 
Ground-beetles, described, 166. 
Grouse locusts, life-history, 92, 
Gryllidas, defined, 97. 
Gryllotalpa, 98. 
Gryllus, species, 99. 
Gypsy moth, 270. 
Gyrinidae, 170. 

Haematobia serrata, 358. 

Hair-streaks, 245. 

Halisidota, species, 268. 

Halteres, of flies, 327. 

Haltica chalybea, 219. 

Ham-beetle, 193. 

Hammer-head borers, 185. 

Harlequin cabbage-bug, 162. 

Harrisina americana, 264. 

Harvest-flies, 139. 

Haustellate mouth-structures, 16. 

Hawk-moths, 254. 

Head and its appendages, 14. 

-louse, 103. 
Hearing of insects, 43. 
Heart, described, 32. 
Heliothini, 303. 
Heliothis armiger, 303. 
Hellebore and its use, 440. 
Hellgrammites, 72. 
Hemerobiidge, described, 72. 
Hemerobius, 74. 
Hemiptera, chapter on, 100. 

defined, 53, 55. 
Hen-hce, 71. 
Hermaphrodites, 46. 
Hesperidae, 254. 
Hessian fly, 336. 

effect of late planting, 428. 
Heterocera, 241, 254. 
Heteromera, defined, 165, 224. 
Heteroptera, defined, 53, 100. 

treated, 150. 
Hickory horned devil, 278. 

phylloxera on, 130. 



Hippiscus discoideus, 88. 
Hippoboscidse, 369. 
Hippodamia, 174, 
Hispidae, 221. 
Histeridae, 180. 
Hive-bee, 414. 
Hog-caterpillars, 257. 

-louse, 104. 
Homoptera, defined, 53, 100, 106. 
Honey-ants, 396. 

-bee, 414. 

-devi^, 126. 

-tubes of plant-lice, 126. 
Hop, Grapta on, 244. 

-louse, life history, 125. 

snout-moth, 306. 
Hopper-dozers, 92, 464. 
Horn-fly, 358. 

-tails, 371, 374. 
Hornets, 406. 
Horse-bot, 351. 

-flies, 342. 
House-fly, 356. 

Household pests, 56, 82, 155, 356, 396. 
Humming-bird hawk-moths, 257. 
Hybernia tiliaria, 308. 
Hydrate of lime, dry, 447. 
Hydrobatidae, defined, 151. 
Hydrocyanic acid gas, 451. 
Hydrophilidas, 170. 
Hymenoptera, chapter on, 370. 

defined, 54, 55. 
Hypena humuli, 306. 
Hyperchiria io, 283. 
Hyper-parasites, 388. 
Hyphantria cunea, 266. 
Hypoderma Hneata, 352. 
Hypopharynx, structure and function, 
16, 43. 

Icerya, Vedalia against, 421. 

purchasi, 108. 
Ichneumon flies, 381. 
Ichneumonidae, 381. 
Ileum, described, 30, 
Indian Cetonia, 204. 
Incomplete metamorphosis, 50. 
Injectors, 433. 
Inoculation of trees, 453. 



474 



IXDEX. 



Insect powder, 442. 

Insecticides, chapter on, 418, 434. 

Insects, defined, 11, 12, 54. 

Insidious flower-bugs, 156. 

Introduced insects, 421. 

Introductor}-, 9. 

lo moth, 284. 

Ipomasa, lar\-« on, 264. 

Ips fasciatus, 181. 

Isabella moth, 266. 

Isomera, defined, 165. 

Isoptera, 64. 

Isosoma species, 386. 

Jassidas, defined, 147. 
Jigger-fleas, 329. 
Joint-worms, 386. 
Jug-handle grubs, 254. 
Jumping plant-hce, 137. 
June-bugs, 200. 

Kainit, against root-lice, 131. 
Katydids, described, 94. 
Kermes, described, 110. 
Kerosene as an insecticide, 442. 

how it kiUs, 38. 
Knapsack pumps, 461. 

Labium, structure and function, 16. 
Labriim, structure and function, 15. 
Lace-\\-ing flies, their habits, etc., 74. 
Lachnostema, 201. 
Lady-birds, described, 172. 
Lastiha coccidivora, 315. 
Lamellate attennas, 21. 
Lamellicomia, defined, 165, 196. 
Lampyridse, 190. 
Lancets of fly mouth, 18. 
Languria mozardi, 176. 
Lantern-flies, described, 146. 
Laphria, species, 344. 
Laphygma frugiperda, 297. 
Larder-beetles, 178. 
Larridae, 403. 

Lan^se distinguished from worms, 11. 
Lai^-al stage, 48. 
Lasioderma serricorne, 193. 
Lasius species, 394. 
Lawns, ants on, 395. 



Leaf-beetles, described, 210. 

-chafers, 199. 

-hoppers, described, 146. 
life-histor}-, 147. 

-roUer caterpillars, 319. 
Leather-beetle, 178. 
Lebia grandis, 168. 
Lecanium, defined, 112. 
Leggett Champion Powder-gun, 455, 
Legs, where located, 25. 

structure of, 25. 
Lema trilineata, 211. 
Leopard-moth, 287. 
Lepidoptera, chapter on, 240. 

defined, 54, 55. 
Lettuce, root-lice on, 127. 
Leucania albilinea, 296. 

unipuncta, 294. 
Lice, biting, their habits, etc., 70. 

on domestic animals, 71, 105. 

sucking, 104. 
Life-histor}s defined, 50. 

economic importance of, 50. 
Ligyrus rugiceps, 203. 
Limacodidse, 271. 
Lime as an insecticide, 432, 446. 

as a preventive, 432. 

salt, and sulphur wash, 448. 

-tree moth, 308. 
Limnophilus rhombicus, 78. 
Litargus, 177. 
Lixus concavus, 230. 
Locomotion, organs of, 25. 
Locust borer, 287. 

leaf-beetle, 222. 
Locustidae, defined, 93. 
Locusts or cicadas, 140. 
Locusts, destructive species, 90. 

remedial measures, 92. 
London purple, analysis of, 435. 
Long-horned beetles, 205. 
Loopers, 307. 

Losses caused by insects, 9. 
Louse-flies, 369. 
Loxostege similalis, 311. 
Lubber grasshoppers, 91. 
Lucanidae, 196. 
Lucanus species, 197. 
Lucillia macellaria, 357. 



INDEX. 



475 



Luna-moth, 282. 
Lycaena, species of, 245. 
Lycaenidae, 242. 
Lygaeidae, defined, 158. 
Lymantriidae defined, 268, 

Machinery, chapter on, 418, 454, 

Macrobasis unicolor, 227. 

Macrodactylus subspinosus, 199. 

Malachiidae, 191. 

Mallophagidae, 70. 

Malpighian tubules, 30. 

Mandibles, structure and function, 15. 

Mandibulate mouth, 15. 

Mantidae, described, 83. 

Mantis religiosa, 84. 

Mantispidae, 76. 

Manure, favors insects, 428. 

podurids breed in, 57. 
Maple-borer, 208. 

clear-wing borer, 262. 

scale, life-history, no. 
March-flies, 340. 
Margaronia nitidalis, 311. 
Mask of dragon-fly larva, 62. 
May-beetles, 200. 

-flies, their habits, etc., 59. 
Maxillae, structure and function, 15. 
McGowen nozzle, 459. 

injector, 463. 
Meadow-grasshoppers, 96. 
Meal-worms, 224. 
Mealy-bugs, described, 106. 

remedies for, 108. 
Measuring-worms, 307. 
Mecoptera, 77. 

Mediterranean flour-moth, 315. 
Megachile species, 412. 
Megathymus yuccas, 254. 
Megatoma, 179. 
Megilla, 174. 
Melanophila, 185. 
Melanoplus atlanis, 90. 

femur-rub rum, 90. 

spretus, 90. 
Melitara dentata, 313. 

prodenialis, 313. 
Melittia ceto, 259. 
Meloidae, 225. 



Melon-louse, life history, 126. 
Melophagus ovinus, 369 
Membracidae, defined, 138. 
Mesothorax, 23. 
Mesograpta polita, 350. 
Metathorax, 23. 
Metamorphosis, defined, 48. 
Microcentrum retinervis, 94. 

laurifolium, 94, 95. 
Microgaster, 383. 
Micro-lepidoptera, 310. 
Micropyle, defined, 47. 
Midaidae, 344. 
Midges, 334, 336. 
Migration in plant-lice, 126. 
Milk-weed butterfly, 242. 
Mineola indiginelia, 313. 

vaccinii, 313. 
Mole-crickets, 98, 
Monilicornia, defined, 165. 
Moniliform antennae, 22, 
Monomorium pharaonis, 396. 
Monophadnus rubi, 374. 
Monostegia rosae, 374. 
Mormon cricket, habits of, 97. 
Mosquitoes, 332. 
Mosquito-hawks, 61. 
Moths, chapter on, 240, 
Moulting of insects, 48. 
Moults, number of, 49. 
Mourning-cloak butterfly, 244. 
Mouth of bees and wasps, 19. 

importance of, 14, 16, 

indicates remedies, 16. 

of flies, 18. 

types of, 14. 
Mud-daubers, 402. 
Multicellular gall, 378. 
Murgantia histrionica, 162. 
Muscidae, 353, 356. 
Muscles, structure and character, 28. 
Mushroom-gnat, 334. 
Mutillidae, 400. 
Mycetophilidae, 334. 
Myrmecocystus melliger, 396. 
Myrmeleonidae, described, 75. 
Myrmicidas, 396. 
Mytilaspis pomorum, 115. 
Myzus cerasi, 134. 



476 



INDEX. 



Nabidae, defined, 153. 
Nabis fusca, 154. 

Naphthaline against book-hce, 69. 

and its uses, 452. 
Natural checks to insect increase, 418, 
Necrophorus, 171. 
Negro-bug, 163. 
Nematus ribesii, 372. 
Nervous centre in flies, 41. 

system of insects, 39. 
Neuroptera, defined, 53, 54. 

chapter on, 58. 

described, 72. 
Neuters in ants, 391. 
Newspaper barriers against borers, 431. 
Nisoniades, species of, 254. 
Nitidulidas, 181. 
Nits of lice, 105. 
Nixon nozzles, 458. 
Noctuidse, 288. 
Notodontidae, 275. 
Notolophus leucostigma, 268. 
Nozzles, types of, 456. 
Nut-weevils, 234. 
Nymph, defined, 49. 
Nymphalidas, 242. 

Oak, Edema albifrons on, 277. 

galls, 377. 

leaf-rollers, 321. 

orange-striped worm on, 278. 

pruners, 207. 
Ocelli, described, 41. 

location of, 22. 
Ocneria dispar, 270. 
Odonata, described, 60. 
Odontota dorsalis, 222. 
CEcanthus species, 100. 
OSdemasia concinna, 277. 
OEdipodinae, described, 87. 
CEsophagus, described, 30. 
CEstridas, 351. 
CEstrus ovis, 352. 
Olfactory organs, described, 44, 
Olfersia, species, 369. 
Oncideres species, 210, 
Onion maggot, 363. 

thrips, 102. 
Ophion species, 382. 



Orange, Aleyrodes on, 122. 
cottony-cushion scale, 108. 
-dog, 253. 

mealy-bugs on, 106. 

oyster-shell scales on, 116. 

red-bug on, 157. 

Termite attack on, 67. 
Orange-striped oak-worm, 278. 
Orbicular spot, 289. 
Orchehmum species, 96. 
Orcus, 174. 

Orders of insects, 52, 54. 
Orgyia leucostigma, 268. 
Ortahds, 365. 

Orthoptera, chapter on, 79. 

defined, 53, 54. 
Orthosoma brunneum, 206. 
Ovaries, described, 46. 
Oviduct, described, 46. 
Oviposition of Acridiidae, 89. 

Chrysopa, 74. 

dragon-flies, 62. 

field-crickets, 99. 

grasshoppers, 89. 

katydids, 96 

locusts, 94. 

tree-crickets, 100, 
Ovipositor, described, 46. 

in crickets, 97. 

of parasites, 379. 
Owlet moths, 288. 
Ox-louse, 104. 
Ox-warble, 352. 

Oxyptilus periscehdactylus, 318. 
Oyster-shell bark-hce, 115. 

Pain in insects, 40. 
Pale-striped flea-beetle, 221. 
Paleacrita species, 308. 
Palm-weevil, 236. 
Palpi, structure and function, 16, 
Pamphila, species of 254. 
Panorpidse, described, 77. 
Paper-making wasps, 406. 
Papilio asterias, 250. 

cresphontes, 253. 

philenor, 251. 

turnus, 252. 
Papilionidas, 246. 



INDEX. 



477 



Papilioninas, 250. 
Parasites on plants, 377. 
Parasitic hymenoptera, 379. 

insects, chapter on, 418. 
Parasitica, defined, loi, 103. 
Paria aterrima, 212. 
Paris green, analysis of, 434. 
Paroxya, 90. 

Parthenogenesis in plant-lice, 123. 
Passalus comutus, 197. 
Pea-weevils, 223. 
Peach-borer, 261. 

-louse, 134. 
Peacock-flies, 365. 
Pear-midge, 339. 

-psylla, life history, 137. 

sinuate borer in, 187. 

-slug. 372. 
Pectinated antennae, 21. 
Peddlers, 222. 
Pediculus species, 103. 
Pelecinus polyturator, 389. 
Pelidnota punctata, 202. 
Pelopoeus species, 402. 
Pemphigus, described, 132. 
Penis of insects, 47. 
Pentatomidse, defined, 162. 
Pentilia misella, 174. 
Pepsis species, 401. 
Perception, sense of, 45. 
Periodical cicada, 140. 
Periplaneta orientalis, 82. 
Perlidae, described, 64. 
Pernicious scale, 118. 
Persian insect powder, 442. 
Pezotettix, 91. 
Phasmidae, described, 84. 
Philampelus achemon, 258. 

pandorus, 258. 
Phorbia brassicae, 361. 

ceparum, 363. 
Phosphorus against roaches, 82. 
Photinus pyralis, 190. 
Phthirius inguinalis, 105. 
Phycitinae, 312. 
Phyllodromia germanica, 82. 
Phylloecus flaviventris, 373. 
Phyllotreta vittata, 221. 
Phylloxera, life history, 128. 



Phymata, habits of, 154. 
Phyniatodes amoenus, 207. 

variabilis, 207. 

variiis, 207. 
Physopoda, loi. 
Phytonomus punctatus, 229. 
Phytophaga, described, 205. 
Phytophagous beetles, defined, 165. 
Pickle-moth, 311. 
Pierinas, 246. 
Pieris protodice, 248. 

rapse, 246. 
Pigeon tremex, 375. 
Pimpla conquisitor, 381. 
Piophila casei, 368. 
Pissodes strobi, 230. 
Plagionotus speciosus, 208. 
Plant-lice, defined, 123. 

life history, 124. 

on roots, 127. 

remedies against, 135. 
Planting, date of, important, 428, 
Platyptera, described, 64. 
Platysamia cecropia, 280. 
Plecoptera, described, 63. 
Pleurum or side, 25. 

Ploughing, to reduce insect injury, 
425- 

Plum-curculio, 232. 
Plume-moths, 318. 
Plumose antennae, 21. 
Plusia brassicae, 302. 

species, 302. 
Podurids, 56. 

Poecilocapsus lineatus, 156. 
Poisers, of flies, 327. 
Polistes species, 406. 
Pollen basket, 408. 
Pollination, due to bees, 408. 
Polyphemus moth, 282. 
Pomace-flies, 367. 
Pompilidae, 400. 
Potash as a winter wash, 450. 
Potato-beetle, old-fashioned, 225. 
striped, 213. 
three-lined, 211. 

flea-beetle, 219. 

stalk-borer, 234. 

scab-gnat, 335. 



478 



INDEX. 



Potato-sphinx, 256. 
Poultry-lice, 71. 
Powder bellows, 455. 
Praying Mantis, habits of, 84. 
Predaceous bugs, 152. 

insects, chapter on, 418. 
Preventives, chapter on, 418, 430, 
Printers-ink bands, 433. 
Prionidus cristatus, 152. 
Prionoxystus robini^, 287. 
Prionus laticollis, 206. 
Proctotrypidae, 387. 
Prolegs, defined, 12, 
Prominents, 275. 
Prothorax, 23. 
Protoparce Carolina, 256. 

celeus, 256. 
Psenocorus supernotatus, 208. 
Pseudo-neuroptera, defined, 53, 54, 58. 
Pseudo-trachea of fly, 20. 
Psocidae, described, 68. 
Psocus lineatus, 69. 
Psychidae, 273. 
Psychomorpha epimenis, 264. 
Psylla pyricola, 137. 
Psyllid^, defined, 137. 
Pteromalus puparum, 385. 
Pterophoridae, 318. 
Ptinidae, 193. 
Pubescent antennas, 22. 
Pulvilli, defined, 26. 
Pulvinaria innumerabilis, 110. 
Pumps, for spraying, 456, 462. 
Punkies, 334. 
Pupa, defined, 49- 
Pupipara, 369. 
Pyralididae, 310. 
Pyralis farinalis, 312. 
Pyrausta species, 311. 
Pyraustidae, 310. 

Pyrethro-kerosene emulsion, 443. 
Pyrethrum and its uses, 442. 
Pyrophila pyramidoides, 299. 
Pyrrharctia Isabella, 266. 

Quassia as an insecticide, 453. 
Queen bees, 415. 
Quince-borer, 209. 
-curculio, 234. 



Radish-maggot, 362. 
Raphidia, 72. 
Raptoria, defined, 81. 
Raspberry, Byturus, 180. 

-slug, 374. 
Rat-tailed larvae, 350. 

how they breathe, 37. 
Raupenleim and dendrolene, 431. 
Receptaculum seminis, 46. 
Rectum, described, 30. 
Red-bug on cotton, 157. 

-humped prominent, 277. 

-legged locust, 90. 

-necked cane-borer, 186. 
Reduviidae, defined, 151. 
Reflowing cranberry bogs, 428. 
Regal walnut-moth, 278. 
Reniform spot, 289. 
Reproduction among insects, 45. 
Resin washes, use and formulas, 447. 
Respiration in insects, 33. 

in dragon-fly larvae, 51. 

in water-beetles, 36. 

economic bearing of, 33, 38. 
Retina, described, 41. 
Rhipiceridae, 182. 
Rhizobiinae, described, 127. 
Rhizobius, 174. 
Rhopalocera, defined, 241. 
Rhopobota vacciniana, 320. 
Rhubarb, weevil on, 230. 
Rhynchophora, 165, 228. 
Rhynchophorus palmarum, 236. 
Roaches, life history, 81. 
Robber-flies, 344. 
Rocky Mountain locust, 90. 
Root-lice, remedies for, 130. 

-maggots, 360. 

web-worms, 317. 
Rose-beetle, Fuller's, 228. 

-bug, 199. 

-chafer, 199. 

leaf-hopper, 148. 

leaf-rollers, 321. 

-scale, 119. 

-slug, 374. 
Rosy Dryocampa, 279. 
Rostrum, defined, 17. 
Rotation, use of, 426, 



INDEX, 



Round-headed borers, 205, 
Rove-beedes, 172. 

Saliva and its uses, 31. 
Salivary glands, 30, 31. 
Saltatoria, defined, 81. 
San Jose scale, 118. 
Sand-crickets, 97. 

-flies. 334. 
Sannina exitiosa, 261. 
Sap-beetles, 181. 
Saperda Candida, 209. 
Sarcophaga carnaria, 355. 
Sarcopsylla, species of, 329, 
Saw-flies, 371. 
Scale insects, 106. 

remedies for, 108, 120. 
Scape of antenna, 22. 
Scavenger beetles, 172, 197. 
Scarabaeidae, 197. 
Scenopinidae, 347. 
Scenopinus fenestralis, 347. 
Schistocerca americana, 89. 

peregrinum, 89. 
Schizoneura, described, 133. 

lanigera, 133. 
Sciara species, 334. 
Sclerites, defined, 23. 
Scoliidae, 400. 
Scolytidae, 237. 
Scolytus rugulosus, 238. 
Scorpion fl.ies, their habits, etc., 77. 
Screw-worm fly, 357. 
Scudderia species, 94. 
Scurfy scale, described, 119. 
Scutelleridae, defined, 163. 
Scymnus species, 174. 
Segments in insects, 311. 
Semi-loopers, 300. 
Seminal receptacle, 46. 
Sensation in insects, 40. 
Sericaria mori, 286. 
Serrate antennae, 21. 
Serricornia, defined, 165. 
Sesia acerni, 262. 

tipuliformis, 263. 
Sesiidse, 259. 

Seventeen-year locust, 140. 
Sex in insects, 46. 



Sheep-bot, 352. 

-tick, 369. 
Sialidae, described, 72. 
Silk-worm, 286. 
Silpha species, 171. 
Silphidas, 171. 
Silvanus surinamensis, 176. 
Silver-fish, 56. 
Simuliidas, 341. 
Sinoxylon, 193. 
Sinuate pear-borer, 187. 
Sitodrepa panicea, 193. 
Skippers, 254. 

in cheese, 368. 
Slugs, beetle larvae, 211. 

saw-fly larvae, 372. 
Smell, sense of, 43. 

organs of, in antennae, 20. 
Snake-doctors, 60, 
Snapping beetles, 182. 
Snout-beetles, described, 228. 

what are, 165. 
Soap mixtures, how they kill, 38, 
Soaps as insecticides, 444. 
Social bees, 414. 

life among Termites, 64. 

wasps, 405. 
Soft scales, described, 110. 
Soldier beetles, 191. 

flies, 343. 
Solitary bees, 407, 
Spanish flies, 225. 
Span-worms, 307. 
Species, defined, 52. 
Sphecidae, defined, 402. 
Sphecius speciosus, 403. 
Sphenophorus, species of, 236, 
Sphex ichneumonea, 403. 
Sphingidas, 254. 
Sphinx Carolina, 256. 

celeus, 256. 
Spilosoma virginica, 266. 
Spiracles, described, 33. 

how protected, 34. 
Spittle insects, 146. 
Spraying machinery, 456. 
Spring-beetles, 182. 

-tails, 53, 56. 
Spotted vine-chafer, 202. 



INDEX. 



Squash-borer, 259. 

-bug, 160. 

lady-bird, 175. 
Stable-fly, 358. 
Stag-beetles, 196. 
Stagmomantis Carolina, 84. 
Staphylinidae, 172. 
Stem-mother in plant-lice, 123, 
Stenopalmatus, 97. 
Sternum or breast, 25. 
Stinging Hymenoptera, 390. 
Stomach poisons, how they act, 32. 
Stomoxys calcitrans, 358. 
Stone-flies, 63. 

Stored produce. Termites in, 67. 
Strategus, 203. 
Stratiomyidae, 343. 
Strawberry-root borers, 212. 

weevil, 231. 
Stridulating organs, 93. 
Striped cucumber-beetle, 214. 
Structure in general, 11. 
Subterranean forms, breathing, 36. 
Sucking lice, 103. 

mouth, 17, 
Sugar-cane beetle, 203. 

borers. 317. 

Termite injury to, 67. 
Sulphur as an insecticide, 452. 
Sutures, defined, 23. 
Swallow-tail butterflies, 250. 
Swarming of bees, what is, 415. 
Sweet-potato flea-beetle, 219. 

tortoise-beetles, 222. 
Syrphidae, 347. 
Systena blanda, 221. 

Tabanidae, 342. 
Tachina flies, 354. 

vivida, 354. 
Tactile organs, what are, 44. 
Tarantula hawk, 401. 
Tarred paper against borers, 431. 
Tarsus, defined, 26. 
Taste in insects, 43. 
Tegmina, defined, 79. 
Telea polyphemus, 281. 
Telephorus, 191. 
Tendon, described, 28. 



Tenebrionidae, 224. 
Tenebrioides, 182. 
Tent-caterpillars, 284. 
Tenthredinidae, 371. 
Teras and its parasites, 420. 

minuta, 319. 
Termes flavipes, 65, 67. 
Termites, their habits, etc., 64. 
Testes, described, 47. 
Tettiginae, described, 91. 
Thalessa species, 379. 
Thecla, species ot, 245. 
Thick-head flies, 351. 
Thorax, structure and function, 23. 
Three-lined potato-beetle, 211. 
Thripidae, defined, loi. 
Thrips, hfe history, 102. 

remedies for, 102. 
Thyridopteryx ephemeraeformis, 273. 
Thysanoptera, defined, loi. 
Thysanura, defined, 53, 54. 

chapter on, 55. 
Tibia, defined, 26. 
Tiger-beetles, described, 166. 
Time of planting, important, 428. 
Tingitidae, defined, 154. 
Tinea pellionella, 325. 
Tineina, defined, 323. 
Tiphia inornata, 400. 
Tipulidas, 330. 
Tobacco and its uses, 440. 

against root-lice, 131. 

beetle, 193. 

sphinx, 256. 

thrips on, 102. 
Tomato fruit-worm, 303. 
Tortoise beetles, 222. 
Tortricids, 319. 
Touch in insects, 44. 
Tracheae, described, 34, 
Tracheal gills, 37. 
Tracheates, defined, 34. 
Transformations, how observed, 50, 
Trap crops, 428. 
Tree-crickets, 100. 

-hoppers, 138. 
Tremex columba, 375. 
Tribolium species, 225. 
Trichobaris 3-notata, 234. 



INDEX. 



Trichogramma pretiosa, 386. 
Trichoptera, defined, 77. ^ 
Triphleps insidiosus, 156. 
Triungulin of meloid larva, 227. 
Trochanter, defined, 26. 

in parasites, 379. 
Trogoderma, 179. 
Trogositidae, 182. 
Trogus exesorius, 381. 
Trox, 199. 

Trypeta pomonella, 366. 
Tryxalinae, described, 87. 
Tubulifera, 390. 
Tumble-bugs, 198. 
Turkey-gnat, 340. 
Turkeys versus grasshoppers, 427. 
Tussock moths, 268. 
Twig-girdlers, 207, 210. 
Two-striped tortoise beetle, 222. 

Under-sprayers, 461. 
Uroceridae, 371, 374. 

Vagina, described, 46. 
Valves of the heart, 32. 
Vanessa antiopa, 244. 
Vaporer moths, 268. 
Vapors as insecticides, 450. 
Vedalia cardinalis, 173. 

versus Icerya, 421. 
Velvet ants, 400. 
Venation, defined, 25. 
Vermipsylla, species of, 329. 
Vermorel nozzle, 456. 
Vespa species, 405, 406. 
Vespidae, 404. 
Vestiture of bees, 408. 
Viviparous plant-lice, 123. 

scale insects, 114. 
Vision of insects, 41, 42. 

Walking-leaves, life history, 85. 

-sticks, life history, 85. 
Washing trees in winter, 433. 
Wasps are beneficial, 407. 
Water as an insecticide, 450. 

-beetles, 169. 



Water-boatman, 150. 

-scavengers, 170. 

-striders, 151. 
Wavy-striped flea-beetle^ 221. 
Waxy scales, 108, 112. 
Web-worms, 266, 311, 317. 
Weevils, defined, 228. 
Whale-oil soap, 445. 
Wheat-head army-worm, 296. 

Hessian fly in, 336. 

-midge, 338. 

saw-fly borer, 376. 

stalk-borer, 299. 
Wheel-bug, described, 152. 
White ants, life history, 64. 

ermine motn, 266. 

-faced wasp, 406, 

-grubs, 196. 

-pine weevil, 230. 
Whitewash, usefulness of, 422. 
Whirligig beetles, 169. 
Willow saw-fly, 374. 
Window flies, 371. 
Winglet, defined, 366. 
Wings, number and location, 12. 

structure of, 25. 
Wings of the heart, 33. 
Winter washing of fruit-trees, 433 
Wire netting against borers, 430. 
W'ire-worms, crane-fly larvae, 331 
described, 182. 
remedies for, 184. 
Woolly apple-louse, 133. 

bears, 265. 

plant-lice, 133. 
W^orker-ants, 391. 
Wrigglers, 332. 

Xiphidium species, 96. 
Xylina antennata, 300. 

species, 300. 
Xylocopa virginica, 412. 
Xyloryctes, 203. 

Yellow-jackets, 405. 

-necked caterpillar, 275. 

Zeuzera pyrina, 287. 



31 



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LIBRARY OF CONGRESS 




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